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Sample records for acidic fens reveal

  1. Complex microbiota of a Chinese "Fen" liquor fermentation starter (Fen-Daqu), revealed by culture-dependent and culture-independent methods

    NARCIS (Netherlands)

    Zheng, X.; Zheng, Y.; Han, B.; Zwietering, M.H.; Samson, R.A.; Boekhout, T.; Nout, M.J.R.

    2012-01-01

    Daqu is a traditional fermentation starter that is used for Chinese liquor production. Although partly mechanized, its manufacturing process has remained traditional. We investigated the microbial diversity of Fen-Daqu, a starter for light-flavour liquor, using combined culture-dependent and culture

  2. Complex microbiota of a Chinese "Fen" liquor fermentation starter (Fen-Daqu), revealed by culture-dependent and culture-independent methods

    NARCIS (Netherlands)

    Zheng, X.W.; Yan, Z.; Han, B.Z.; Zwietering, M.H.; Samson, R.A.; Boekhout, T.; Nout, M.J.R.

    2012-01-01

    Daqu is a traditional fermentation starter that is used for Chinese liquor production. Although partly mechanized, its manufacturing process has remained traditional. We investigated the microbial diversity of Fen- Daqu, a starter for light-flavour liquor, using combined culture-dependent and cultur

  3. Genomic and protein expression analysis reveals Flap endonuclease 1 (FEN1) as a key biomarker in breast and ovarian cancer

    Science.gov (United States)

    Abdel-Fatah, Tarek MA; Russell, Roslin; Albarakati, Nada; Maloney, David J; Dorjsuren, Dorjbal; Rueda, Oscar M; Moseley, Paul; Mohan, Vivek; Sun, Hongmao; Abbotts, Rachel; Mukherjee, Abhik; Agarwal, Devika; Illuzzi, Jennifer L.; Jadhav, Ajit; Simeonov, Anton; Ball, Graham; Chan, Stephen; Caldas, Carlos; Ellis, Ian O; Wilson, David M; Madhusudan, Srinivasan

    2015-01-01

    FEN1 has key roles in Okazaki fragment maturation during replication, long patch base excision repair, rescue of stalled replication forks, maintenance of telomere stability and apoptosis. FEN1 may be dysregulated in breast and ovarian cancers and have clinicopathological significance in patients. We comprehensively investigated FEN1 mRNA expression in multiple cohorts of breast cancer [training set (128), test set (249), external validation (1952)]. FEN1 protein expression was evaluated in 568 oestrogen receptor (ER) negative breast cancers, 894 ER positive breast cancers and 156 ovarian epithelial cancers. FEN1 mRNA overexpression was highly significantly associated with high grade (p=4.89 × 10−57), high mitotic index (p=5.25 × 10−28), pleomorphism (p=6.31 × 10−19), ER negative (p=9.02 × 10−35), PR negative (p=9.24 × 10−24), triple negative phenotype (p=6.67 × 10−21), PAM50.Her2 (p=5.19 × 10−13), PAM50.Basal (p=2.7 × 10−41), PAM50.LumB (p=1.56 × 10−26), integrative molecular cluster 1 (intClust.1) (p=7.47 × 10−12), intClust.5 (p=4.05 × 10−12) and intClust. 10 (p=7.59 × 10−38) breast cancers. FEN1 mRNA overexpression is associated with poor breast cancer specific survival in univariate (p= 4.4 × 10−16) and multivariate analysis (p= 9.19 × 10−7). At the protein level, in ER positive tumours, FEN1 overexpression remains significantly linked to high grade, high mitotic index and pleomorphism (ps<0.01). In ER negative tumours, high FEN1 is significantly associated with pleomorphism, tumour type, lymphovascular invasion, triple negative phenotype, EGFR and HER2 expression (ps<0.05). In ER positive as well as in ER negative tumours, FEN1 protein overexpression is associated with poor survival in univariate and multivariate analysis (ps<0.01). In ovarian epithelial cancers, similarly, FEN1 overexpression is associated with high grade, high stage and poor survival (ps<0.05). We conclude that FEN1 is a promising biomarker in breast

  4. Genomic and protein expression analysis reveals flap endonuclease 1 (FEN1) as a key biomarker in breast and ovarian cancer.

    Science.gov (United States)

    Abdel-Fatah, Tarek M A; Russell, Roslin; Albarakati, Nada; Maloney, David J; Dorjsuren, Dorjbal; Rueda, Oscar M; Moseley, Paul; Mohan, Vivek; Sun, Hongmao; Abbotts, Rachel; Mukherjee, Abhik; Agarwal, Devika; Illuzzi, Jennifer L; Jadhav, Ajit; Simeonov, Anton; Ball, Graham; Chan, Stephen; Caldas, Carlos; Ellis, Ian O; Wilson, David M; Madhusudan, Srinivasan

    2014-10-01

    FEN1 has key roles in Okazaki fragment maturation during replication, long patch base excision repair, rescue of stalled replication forks, maintenance of telomere stability and apoptosis. FEN1 may be dysregulated in breast and ovarian cancers and have clinicopathological significance in patients. We comprehensively investigated FEN1 mRNA expression in multiple cohorts of breast cancer [training set (128), test set (249), external validation (1952)]. FEN1 protein expression was evaluated in 568 oestrogen receptor (ER) negative breast cancers, 894 ER positive breast cancers and 156 ovarian epithelial cancers. FEN1 mRNA overexpression was highly significantly associated with high grade (p = 4.89 × 10(-57)), high mitotic index (p = 5.25 × 10(-28)), pleomorphism (p = 6.31 × 10(-19)), ER negative (p = 9.02 × 10(-35)), PR negative (p = 9.24 × 10(-24)), triple negative phenotype (p = 6.67 × 10(-21)), PAM50.Her2 (p = 5.19 × 10(-13)), PAM50. Basal (p = 2.7 × 10(-41)), PAM50.LumB (p = 1.56 × 10(-26)), integrative molecular cluster 1 (intClust.1) (p = 7.47 × 10(-12)), intClust.5 (p = 4.05 × 10(-12)) and intClust. 10 (p = 7.59 × 10(-38)) breast cancers. FEN1 mRNA overexpression is associated with poor breast cancer specific survival in univariate (p = 4.4 × 10(-16)) and multivariate analysis (p = 9.19 × 10(-7)). At the protein level, in ER positive tumours, FEN1 overexpression remains significantly linked to high grade, high mitotic index and pleomorphism (ps cancers, similarly, FEN1 overexpression is associated with high grade, high stage and poor survival (ps breast and ovarian epithelial cancer.

  5. Concepts of fen and bog re-examined in relation to bryophyte cover and the acidity of surface waters

    Directory of Open Access Journals (Sweden)

    Eville Gorham

    2014-01-01

    Full Text Available Studies of surface-water pH and bryophyte assemblages in 440 plots from five peatland regions across northern North America reveal a very distinct, two-fold division into fens with a pH mode at 6.76-7.00, in which Amblystegiaceae are prominent, and bogs with a pH mode at 4.01-4.25, in which Sphagnaceae are dominant. The relevance of the data to past and current views on peatland classification is explored.

  6. Acid-tolerant microaerophilic Fe(II)-oxidizing bacteria promote Fe(III)-accumulation in a fen.

    Science.gov (United States)

    Lüdecke, Claudia; Reiche, Marco; Eusterhues, Karin; Nietzsche, Sandor; Küsel, Kirsten

    2010-10-01

    The ecological importance of Fe(II)-oxidizing bacteria (FeOB) at circumneutral pH is often masked in the presence of O(2) where rapid chemical oxidation of Fe(II) predominates. This study addresses the abundance, diversity and activity of microaerophilic FeOB in an acidic fen (pH ∼ 5) located in northern Bavaria, Germany. Mean O(2) penetration depth reached 16 cm where the highest dissolved Fe(II) concentrations (up to 140 µM) were present in soil water. Acid-tolerant FeOB cultivated in gradient tubes were most abundant (10(6) cells g(-1) peat) at the 10-20 cm depth interval. A stable enrichment culture was active at up to 29% O(2) saturation and Fe(III) accumulated 1.6 times faster than in abiotic controls. An acid-tolerant, microaerophilic isolate (strain CL21) was obtained which was closely related to the neutrophilic, lithoautotrophic FeOB Sideroxydans lithotrophicus strain LD-1. CL21 oxidized Fe(II) between pH 4 and 6.0, and produced nanoscale-goethites with a clearly lower mean coherence length (7 nm) perpendicular to the (110) plane than those formed abiotically (10 nm). Our results suggest that an acid-tolerant population of FeOB is thriving at redox interfaces formed by diffusion-limited O(2) transport in acidic peatlands. Furthermore, this well-adapted population is successfully competing with chemical oxidation and thereby playing an important role in the microbial iron cycle.

  7. Seed dispersal in fens

    NARCIS (Netherlands)

    Middleton, Beth; van Diggelen, Rudy; Jensen, Kai

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and redu

  8. Seed dispersal in fens

    Science.gov (United States)

    Middleton, B.; Van Diggelen, R.; Jensen, K.

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can lead to biodiversity loss. While fens may have always been relatively isolated from each other, they have become increasingly fragmented in modern times within agricultural and urban landscapes in both Europe and North America. Dispersal by water, animals and wind has been hampered by changes related to development in landscapes surrounding fens. Because the seeds of certain species are long-lived in the seed bank, frequent episodes of dispersal are not always necessary to maintain the biodiversity of fens. However, of particular concern to restoration is that some dominant species, such as the tussock sedge Carex stricta, may not disperse readily between fens. Conclusions: Knowledge of seed dispersal can be used to maintain and restore the biodiversity of fens in fragmented landscapes. Given that development has fragmented landscapes and that this situation is not likely to change, the dispersal of seeds might be enhanced by moving hay or cattle from fens to damaged sites, or by reestablishing lost hydrological connections. ?? IAVS; Opulus Press.

  9. Ecoenzymatic stoichiometry and microbial processing of organic matter in northern bogs and fens reveals a common P limitation among peatland types

    Science.gov (United States)

    We compared C, N, and P concentrations in atmospheric deposition, runoff, and soil standing stocks with microbial respiration (DHA) and ecoenzyme activity (EEA) in an ombrotrophic bog (S2) and a minerotrophic fen (S3) to investigate the environmental drivers of biogeochemical cyc...

  10. Método para a Determinação de Ácidos Fenólicos na Parede Celular de Forragens Method for Phenolic Acid Determination in Forage Cell Wall

    Directory of Open Access Journals (Sweden)

    Francisco Carlos Deschamps

    2002-07-01

    Full Text Available Há fatores que limitam a digestão das forragens tropicais e estão associados à dinâmica dos ácidos fenólicos da parede celular. Os estudos destes compostos em forragens podem ser facilitados pela disponibilidade de métodos sensíveis que permitam o processamento de grande número de amostras. No presente trabalho, descreve-se um método para a determinação de ácidos fenólicos na parede celular de forragens, utilizando cromatografia líquida de alta eficiência (CLAE. Bagaço de cana, capim-elefante e folhas de mandioca foram utilizados como amostras experimentais. Para remover substâncias solúveis de baixa massa molecular, foram testados etanol 80% e o detergente neutro, determinando seus efeitos sobre a recuperação das moléculas e benefícios no perfil cromatográfico. Para a obtenção dos ácidos fenólicos livres, as amostras foram solubilizadas em NaOH 1 mol/L, 20ºC por 24 horas. O método proposto foi adequado para a determinação de ácidos fenólicos, apresentando grande sensibilidade e produtividade no laboratório. Para minimizar os efeitos negativos da formação de sal resultante da neutralização ácida do extrato alcalino, sugere-se a diluição da amostra ou a injeção de pequeno volume (5 uL no aparelho. O efeito da utilização de solventes como etanol 80% ou detergente neutro é distinto sobre as amostras das gramíneas e leguminosas. A quantidade de extrativos nas folhas de mandioca foi superior a do bagaço de cana e capim-elefante. A concentração de ácidos fenólicos foi pouco alterada pela ação dos solventes, sendo maior nas amostras de bagaço de cana e capim-elefante, em relação às folhas de mandioca. O método apresentado constitui-se em uma importante ferramenta para o estudo dos ácidos fenólicos na parede celular de forragens tropicais.Factors that limit the digestion of tropical forages are associated to the dynamic of cell wall phenolic acids. The study of these compounds in forages may

  11. 利用醋酸发酵液提高清香型白酒中酸酯含量的研究%Improving the content of acids and esters of fen-flavor liquor using ending liquor

    Institute of Scientific and Technical Information of China (English)

    王文阳; 肖冬光; 杜丽平; 张艳英; 陈原

    2012-01-01

    Using ending liquor of fen-flavor liquor's by products as the main components of the medium, the acetic acid liquid by acetic fermentation was obtained, and then utilized in the production of fen-liquor. The effects of adding amount of acetic acid liquid on fermentation and contents of acids and esters of fen-flavor liquor were studied. The results were as follows: Adding acetic acid liquid increased the acidity of the fermented grains, resulted to the alcohol content decreased slightly in the fermented grains, but adding acetic acid liquid could improve the main acids and esters significantly. According to the physiochemical parameters, when adding acetic acid liquid and made the acidity of the fermented grains reached 3.0mg/g, the acids and esters improved significantly, the acetic acid and ethyl acetate increased by 138.35% and 85.43%, respectively, and the total esters of two fermentations increased by 25.93%.%以清香型白酒生产的副产物大曲酒尾为培养基主要成分,经醋酸发酵制取醋酸发酵液,将其应用于清香型白酒生产中,通过考察醋酸发酵液的添加量,研究了其对酒醅发酵和清香型白酒酸酯含量的影响.试验结果表明,采用“清蒸二次清”工艺,在大(米查)酒醅发酵时添加醋酸发酵液,发酵结束后大(米查)酒醅酒精度略微下降,但添加醋酸发酵液可明显提高大渣酒中的主体酸酯含量;二(米查)酒醅发酵按照传统工艺进行,发酵结束后二(米查)酒醅酒精度呈增加趋势,二(米查)酒中的酸酯含量与对照无明显变化.理化指标结果表明,当醋酸发酵液添加量使大(米查)酒醅含量为3.0mg醋酸/g醅时,酒中主体酸酯含量提高较为显著,大(米查)酒中乙酸和乙酸乙酯分别提高了138.35%和85.43%,2次发酵总酯提高了25.93%.

  12. Calcareous Fens - Source Feature Points

    Data.gov (United States)

    Minnesota Department of Natural Resources — Pursuant to the provisions of Minnesota Statutes, section 103G.223, this database contains points that represent calcareous fens as defined in Minnesota Rules, part...

  13. the Fe-N System

    Directory of Open Access Journals (Sweden)

    S. Matar

    1993-01-01

    of Fe2N for the two nitrides. The magnetization is low (0.95 μB/at. for Fe2N and vanishes for FeN. The decrease of the magnetization with increasing amount of N is assessed within the Fe-N system in a model derived from a Slater-Pauling type behavior. Accordingly, a trend from weak to strong ferromagnetism is suggested.

  14. Actividad antioxidante de los compuestos fenólicos

    Directory of Open Access Journals (Sweden)

    Maestro Durán, R.

    1993-04-01

    Full Text Available This review deals with the oxidation processes induced by light and atmospheric oxygen, as well as the protective action on antioxidant compounds. The available data on the synthetic antioxidants and the problems associated to their use, together with the presence of natural phenolic antioxidants in plants, have been revised. These phenolic antioxidants have been classified in families: phenolic alcohols and acids, cinnamic acids, coumarins, favonoids (flavones and isoflavones, flavonols, flavanones and other phenolic compounds.

    Este trabajo recoge los estudios sobre los mecanismos de oxidación producida por la luz y el oxígeno del aire y sobre la protección de los compuestos antioxidantes contra esta oxidación. Se han revisado los datos existentes sobre los inconvenientes de los antioxidantes sintéticos, que aconsejan sustituirlos por otros naturales y sobre la presencia de antioxidantes naturales de carácter fenólico en las plantas. Los antioxidantes fenólicos se han agrupado por familias: alcoholes y ácidos fenólicos, ácidos cinámicos, cumarinas, flavonoides (flavonas e isoflavonas, flavonoles, flavanonas y otros compuestos fenólicos.

  15. Actividad antioxidante, compuestos fenólicos y ácido ascórbico de frutillas en dos sistemas de producción Antioxidant activity, phenolic compounds and ascorbic acid content in strawberries from two crop production systems

    Directory of Open Access Journals (Sweden)

    Rufino Fernando F Cantillano

    2012-12-01

    Full Text Available El objetivo de este trabajo fue determinar la influencia del sistema de producción y del período de almacenamiento de frutillas sobre la pérdida de masa, compuestos fenólicos totales, antocianinas totales, ácido ascórbico (vitamina C, actividad antioxidante y sus correlaciones. En este experimento fueron utilizadas frutillas 'Camarosa' y 'Camino Real' con madurez comercial, procedentes de cultivos en sistemas de producción orgánico y convencional, localizados en el municipio de Pelotas-RS. Los frutos fueron almacenados durante 0, 2, 5 y 8 días a 1ºC y 90-95% de HR. En general, el contenido de fenoles totales, de antocianinas totales y la actividad antioxidante aumentaron durante el almacenamiento refrigerado, mientras que los contenidos de ácido ascórbico y de masa fresca disminuyeron significativamente. Los contenidos de fenoles totales y de antocianinas totales presentaron correlación positiva con la actividad antioxidante, siendo la correlación con el contenido de ácido ascórbico negativa. Las frutillas producidas en sistema orgánico y conservadas durante cinco días, mostraron mayores valores de actividad antioxidante. Después de ocho días de almacenamiento a 1ºC, los frutos del sistema de producción orgánico presentaron menor degradación de antocianinas y de ácido ascórbico que los frutos del sistema de producción convencional.The aim of this study was to determine the influence of the crop production system and storage period on weight loss, total phenolic content, total anthocyanin content, ascorbic acid (vitamin C content, and antioxidant activity in strawberries, as well as their correlations. For this experiment, strawberry fruits of 'Camarosa' and 'Camino Real' at commercial maturity from both organic and conventional crop production systems located in Pelotas, Brazil, were used. The fruits were cold stored for 0, 2, 5, and 8 days at 1ºC and 90-95% RH. In general the total phenolic, total anthocyanin levels

  16. Unravelling hydrological mechanisms behind fen deterioration

    NARCIS (Netherlands)

    van Loon, A.H.

    2010-01-01

    Low-productive fens are wetland ecosystems that have strongly declined in number and size in temperate regions of Western Europe since World War II. This fen type has significant conservation value in many countries because of its high species diversity and the presence of endangered plant species.

  17. Effect of Groundwater Abstraction on Fen Ecosystems

    DEFF Research Database (Denmark)

    Johansen, Ole; Pedersen, Morten Lauge; Jensen, Jacob Birk

    2011-01-01

    hydrological conditions have been monitored intensively since March 2007. In the early spring 2009 two full scale pumping test were conducted in the regional high yield limestone aquifer. The evaluation focuses on three isolated fens covering an area of approximately 5000 m2 each and two natural springs all...... and spring habitats. Continuous water level data from deep and shallow wells in the fens reflect the hydrological conditions. Large differences in water level drawdown during dry summer periods have been observed in the monitored fens and it is hypothesised, that these differences are directly related...... of the monitored ecosystems and the response towards groundwater abstraction and forms a solid foundation for hydrological modelling....

  18. Conservation and Biodiversity of Rich Fens

    DEFF Research Database (Denmark)

    Andersen, Dagmar Kappel

    2014-01-01

    Rich fen is a habitat type dependent on a constant supply of nutrient poor, calcium rich groundwater. A high, stable groundwater table, relatively high pH combined with nutrient poor conditions support a special and very species rich vegetation including many rare and threatened plant species....... In NW Europe, the majority of rich fens are to some extent impacted by drainage and/or increased nutrient availability (eutrophication), which entails that more competitive species appear at the expense of the characteristic rich fen species. This PhD thesis presents results from studies...

  19. Evolutionary engineering reveals divergent paths when yeast is adapted to different acidic environments

    DEFF Research Database (Denmark)

    Fletcher, Eugene; Feizi, Amir; Bisschops, Markus M. M.

    2017-01-01

    Tolerance of yeast to acid stress is important for many industrial processes including organic acid production. Therefore, elucidating the molecular basis of long term adaptation to acidic environments will be beneficial for engineering production strains to thrive under such harsh conditions....... Previous studies using gene expression analysis have suggested that both organic and inorganic acids display similar responses during short term exposure to acidic conditions. However, biological mechanisms that will lead to long term adaptation of yeast to acidic conditions remains unknown and whether...... sequencing and RNA-seq analysis of the evolved strains revealed different sets of genome alterations suggesting a divergence in adaptation to these two acids. An altered sterol composition and impaired iron uptake contributed to HCl tolerance whereas the formation of a multicellular morphology and rapid...

  20. Geochemistry and hydrology of a calcareous fen within the Savage Fen wetlands complex, Minnesota, USA

    Science.gov (United States)

    Komor, S.C.

    1994-01-01

    Savage Fen is a wetlands complex at the base of north-facing bluffs in the Minnesota River Valley. The complex includes 27.8 hectares of calcareous fen that host rare calciphile plants whose populations are declining in Minnesota. Water and sediment compositions in the calcareous fen were studied to gain a better understanding of the hydrologie System that sustains the rare vegetation. Groundwater in the fen is a calcium-magnesium-bicarbonate type with circumneutral pH values. The groundwater composition is the resuit of interactions among water, dissolved and gaseous carbon species, carbonates, and ion exchangers. Shallow groundwater is distinguished from deep groundwater by smaller concentrations of chloride, sulfate, magnesium, and sodium, and larger concentrations of calcium, bicarbonate, hydrogen sulfide, and ammonium. Magnesian calcite is the prevalent carbonate in unconsolidated sedimentary fill beneath the fen and is an important source and sink for dissolved calcium, magnesium, and inorganic carbon. Calcite concentrations just below the water table are small because aerobic and anaerobic oxidation of organic matter increase the partial pressure of carbon dioxide (PCO2), decrease pH, and cause calcite to dissolve. Thick calcite accumulations just above the water table, in the root zone of calciphile plants, result from water table fluctuations and attendant changes in PCO2. Groundwater beneath Savage Fen recharges in lakes and ponds south of the fen and upwells to the surface within the fen. Water at the water table is a mixture of upwelling groundwater and water near the surface that flows downslope from higher elevations in the fen. Changes in oxygen and hydrogen isotope compositions of shallow groundwater indicate that the proportion of upwelling groundwater in shallow groundwater decreases downgradient in the calcareous fen. Encroachment of reed grasses into the calcareous fen may reflect human-caused disturbances in the recharge area.

  1. Biodiversity management of fens and fen meadows by grazing, cutting and burning

    NARCIS (Netherlands)

    Middleton, Beth A.; Holsten, Bettina; van Diggelen, Rudy

    2006-01-01

    Question: Can the biodiversity of fens in Europe and North America be maintained through the use of grazing (especially cattle grazing), fire, and/or cutting? Location: European and North American fens. Methods: This paper is a review of the literature on the effects of grazing, fire and cutting on

  2. Fine Structure of Hydrogen Bond in Cholic Acid Revealed by 2DIR Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on cryogenic FT-IR spectroscopic studies of hydrogen bonds in cholic acid, two-dimensional FT-IR spectroscopy was applied to enhance our understanding of the hydrogen bonds of cholic acid. Fine spectral structures were revealed by asynchronous 2D FT-IR spectra. The co-relationship among various bands was discussed according to the synchronous 2D FT-IR spectrum.

  3. Analysis of putative nonulosonic acid biosynthesis pathways in Archaea reveals a complex evolutionary history.

    Science.gov (United States)

    Kandiba, Lina; Eichler, Jerry

    2013-08-01

    Sialic acids and the other nonulosonic acid sugars, legionaminic acid and pseudaminic acid, are nine carbon-containing sugars that can be detected as components of the glycans decorating proteins and other molecules in Eukarya and Bacteria. Yet, despite the prevalence of N-glycosylation in Archaea and the variety of sugars recruited for the archaeal version of this post-translational modification, only a single report of a nonulosonic acid sugar in an archaeal N-linked glycan has appeared. Hence, to obtain a clearer picture of nonulosonic acid sugar biosynthesis capability in Archaea, 122 sequenced genomes were scanned for the presence of genes involved in the biogenesis of these sugars. The results reveal that while Archaea and Bacteria share a common route of sialic acid biosynthesis, numerous archaeal nonulosonic acid sugar biosynthesis pathway components were acquired from elsewhere via various routes. Still, the limited number of Archaea encoding components involved in the synthesis of nonulosonic acid sugars implies that such saccharides are not major components of glycans in this domain.

  4. Formalized classification of European fen vegetation at the alliance level

    NARCIS (Netherlands)

    Peterka, Tomáš; Hájek, Michal; Jiroušek, Martin; Jiménez-Alfaro, Borja; Aunina, Liene; Bergamini, Ariel; Dítě, Daniel; Felbaba-Klushyna, Ljuba; Graf, Ulrich; Hájková, Petra; Hettenbergerová, Eva; Ivchenko, Tatiana G.; Jansen, Florian; Koroleva, Natalia E.; Lapshina, Elena D.; Lazarević, Predrag M.; Moen, Asbjørn; Napreenko, Maxim G.; Pawlikowski, Paweł; Plesková, Zuzana; Sekulová, Lucia; Smagin, Viktor A.; Tahvanainen, Teemu; Thiele, Annett; Biţǎ-Nicolae, Claudia; Biurrun, Idoia; Brisse, Henry; Ćušterevska, Renata; Bie, De Els; Ewald, Jörg; FitzPatrick, Úna; Font, Xavier; Jandt, Ute; Kącki, Zygmunt; Kuzemko, Anna; Landucci, Flavia; Moeslund, Jesper E.; Pérez-Haase, Aaron; Rašomavičius, Valerijus; Rodwell, John S.; Schaminée, Joop H.J.; Šilc, Urban; Stančić, Zvjezdana; Chytrý, Milan; Schwabe-Kratochwil, Angelika

    2017-01-01

    Aims: Phytosociological classification of fen vegetation (Scheuchzerio palustris-Caricetea fuscae class) differs among European countries. Here we propose a unified vegetation classification of European fens at the alliance level, provide unequivocal assignment rules for individual vegetation plots,

  5. Formalized classification of European fen vegetation at the alliance level

    DEFF Research Database (Denmark)

    Peterka, Tomáš; Hájek, Michal; Jiroušek, Martin

    2017-01-01

    Aims Phytosociological classification of fen vegetation (Scheuchzerio palustris-Caricetea fuscae class) differs among European countries. Here we propose a unified vegetation classification of European fens at the alliance level, provide unequivocal assignment rules for individual vegetation plots...

  6. Biosorption of Metallic Elements onto Fen Peat

    Directory of Open Access Journals (Sweden)

    Krumins Janis

    2014-12-01

    Full Text Available Industrial development and anthropogenic activity have a huge impact on the environment, forcing society to find new and cost-effective environment treatment technologies. One of the most effective and environmentally friendly methods is the use of biosorbents, for which peat is one of the most cost-effective materials. The adsorption capabilities of peat sediments are well known; however, mainly raised bog peat is used for environmental treatment, and thus the abilities of fen peat are underestimated. The aim of this research was to assess the fen peat suitability as an adsorbent for metallic elements. In this study we have determined the sorption characteristics of Ca, Mg, K, Na, Cu and Pb and results show that fen peat deposits have a huge variability as a biosorbent due to their variable botanical composition and complex properties, for instance, under equal conditions, wood-sedge peat can have higher lead adsorption capacity than wood peat. However, due to its natural content of metallic elements, the sorption capacity overall is lower than it is for raised bog peat, although the high pH reaction encourage a high mobility metals.

  7. Regional scale hydrological and biogeochemical processes controlling high biodiversity of a groundwater fed alkaline fen

    Science.gov (United States)

    van der Zee, Sjoerd E. A. T. M.; (D. G.) Cirkel, Gijsbert; (J. P. M) witte, Flip

    2014-05-01

    The high floral biodiversity of groundwater fed fens and mesotrophic grasslands depends on the different chemical signatures of the shallow rainwater fed topsoil water and the slightly deeper geochemically affected groundwater. The relatively abrupt gradients between these two layers of groundwater enable the close proximity of plants that require quite different site factors and have different rooting depths. However, sulphur inflow into such botanically interesting areas is generally perceived as a major threat to biodiversity. Although in Europe atmospheric deposition of sulphur has decreased considerably over the last decades, groundwater pollution by sulphate may still continue due to pyrite oxidation in soil as a result of excessive fertilisation. Inflowing groundwater rich in sulphate can change biogeochemical cycling in nutrient-poor wetland ecosystems because of 'so called' internal eutrophication as well as the accumulation of dissolved sulphide, which is phytotoxic. Complementary to conventions, we propose that upwelling sulphate rich groundwater may, in fact, promote the conservation of rare and threatened alkaline fens: excessive fertilisation and pyrite oxidation also produces acidity, which invokes calcite dissolution, and increased alkalinity and hardness of the inflowing groundwater. For a very species-rich wetland nature reserve, we show that sulphate is reduced and effectively precipitated as iron sulphides, when this calcareous and sulphate rich groundwater flows upward through the organic soil of the investigated nature reserve. Also, we show that sulphate reduction occurs simultaneously with an increase in alkalinity production, which in our case results in active calcite precipitation in the soil. In spite of the occurring sulphate reduction, we found no evidence for internal eutrophication. Extremely low phosphorous concentration in the pore water could be attributed to a high C:P ratio of soil organic matter and co-precipitation with

  8. Elastoviscous Transitions of Articular Cartilage Reveal a Mechanism of Synergy between Lubricin and Hyaluronic Acid.

    Directory of Open Access Journals (Sweden)

    Edward D Bonnevie

    Full Text Available When lubricated by synovial fluid, articular cartilage provides some of the lowest friction coefficients found in nature. While it is known that macromolecular constituents of synovial fluid provide it with its lubricating ability, it is not fully understood how two of the main molecules, lubricin and hyaluronic acid, lubricate and interact with one another. Here, we develop a novel framework for cartilage lubrication based on the elastoviscous transition to show that lubricin and hyaluronic acid lubricate by distinct mechanisms. Such analysis revealed nonspecific interactions between these molecules in which lubricin acts to concentrate hyaluronic acid near the tissue surface and promotes a transition to a low friction regime consistent with the theory of viscous boundary lubrication. Understanding the mechanics of synovial fluid not only provides insight into the progression of diseases such as arthritis, but also may be applicable to the development of new biomimetic lubricants.

  9. Elastoviscous Transitions of Articular Cartilage Reveal a Mechanism of Synergy between Lubricin and Hyaluronic Acid.

    Science.gov (United States)

    Bonnevie, Edward D; Galesso, Devis; Secchieri, Cynthia; Cohen, Itai; Bonassar, Lawrence J

    2015-01-01

    When lubricated by synovial fluid, articular cartilage provides some of the lowest friction coefficients found in nature. While it is known that macromolecular constituents of synovial fluid provide it with its lubricating ability, it is not fully understood how two of the main molecules, lubricin and hyaluronic acid, lubricate and interact with one another. Here, we develop a novel framework for cartilage lubrication based on the elastoviscous transition to show that lubricin and hyaluronic acid lubricate by distinct mechanisms. Such analysis revealed nonspecific interactions between these molecules in which lubricin acts to concentrate hyaluronic acid near the tissue surface and promotes a transition to a low friction regime consistent with the theory of viscous boundary lubrication. Understanding the mechanics of synovial fluid not only provides insight into the progression of diseases such as arthritis, but also may be applicable to the development of new biomimetic lubricants.

  10. Land cover or climate? In search of dominant factors inducing groundwater recharge and fen hydrology in European scale

    Science.gov (United States)

    Grygoruk, Mateusz; Kotowski, Wiktor

    2016-04-01

    Groundwater recharge plays the crucial role in development and stability of fens. It was hypothesized that the mid- and late-Holocene acceleration of fens' development in Europe could have been induced by changes in land cover: decreasing areas of forests resulting from the expanding agriculture have enhanced groundwater recharge by decreasing evapotranspiration and interception and promoting infiltration. However, regardless human-related changes of the landscape, recorded climatic fluctuations could also be considered as drivers of changing groundwater recharge that affects fen stability and development. Nowadays, when up to 90% of European wetlands is considered degraded, assessing vulnerability of groundwater recharge to changing landscape and climate is of the crucial importance for setting fen restoration and management strategies. Main goal of our study was to assess the magnitude of changes in groundwater recharge estimation resulting from modelled changes of the landscape and climatic features in >300 fens located in Poland, Germany, The Netherlands, Sweden, UK and Norway. In our approach we (1) delineated the most probable extents of catchments of particular fens analysed, (2) assumed hypothetical and the most probable changes of land cover within these catchments, (3) assumed the most probable ranges of climatic changes in each of the catchments including historical reconstructions (Holocene) and future projections (A1B scenario, CSIRO:MK3 and UKMO:HADCM3 GCM-RCM ensembles), (4) developed, tested and calibrated automatic, GIS-based groundwater recharge calculation algorithm to be applied in the study, (5) calculated groundwater recharge in multiple probable combinations of landscape and climatic conditions and (6) performed statistical analysis in order to reveal whether the climate or landscape changes were the dominant factors that could have probably influenced groundwater recharge in catchments of fens analysed. We revealed that in the case of 80% of

  11. Bile acid-induced virulence gene expression of Vibrio parahaemolyticus reveals a novel therapeutic potential for bile acid sequestrants.

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    Kazuyoshi Gotoh

    Full Text Available Vibrio parahaemolyticus, a bacterial pathogen, causes human gastroenteritis. A type III secretion system (T3SS2 encoded in pathogenicity island (Vp-PAI is the main contributor to enterotoxicity and expression of Vp-PAI encoded genes is regulated by two transcriptional regulators, VtrA and VtrB. However, a host-derived inducer for the Vp-PAI genes has not been identified. Here, we demonstrate that bile induces production of T3SS2-related proteins under osmotic conditions equivalent to those in the intestinal lumen. We also show that bile induces vtrA-mediated vtrB transcription. Transcriptome analysis of bile-responsive genes revealed that bile strongly induces expression of Vp-PAI genes in a vtrA-dependent manner. The inducing activity of bile was diminished by treatment with bile acid sequestrant cholestyramine. Finally, we demonstrate an in vivo protective effect of cholestyramine on enterotoxicity and show that similar protection is observed in infection with a different type of V. parahaemolyticus or with non-O1/non-O139 V. cholerae strains of vibrios carrying the same kind of T3SS. In summary, these results provide an insight into how bacteria, through the ingenious action of Vp-PAI genes, can take advantage of an otherwise hostile host environment. The results also reveal a new therapeutic potential for widely used bile acid sequestrants in enteric bacterial infections.

  12. Transcriptome analysis of sorbic acid-stressed Bacillus subtilis reveals a nutrient limitation response and indicates plasma membrane remodeling

    NARCIS (Netherlands)

    A. ter Beek; B.J.F. Keijser; A. Boorsma; A. Zakrzewska; R. Orij; G.J. Smits; S. Brul

    2008-01-01

    The weak organic acid sorbic acid is a commonly used food preservative, as it inhibits the growth of bacteria, yeasts, and molds. We have used genome-wide transcriptional profiling of Bacillus subtilis cells during mild sorbic acid stress to reveal the growth-inhibitory activity of this preservative

  13. Critical role for CaFEN1 and CaFEN12 of Candida albicans in cell wall integrity and biofilm formation

    Science.gov (United States)

    Alfatah, Md.; Bari, Vinay K.; Nahar, Anubhav S.; Bijlani, Swati; Ganesan, K.

    2017-01-01

    Sphingolipids are involved in several cellular functions, including maintenance of cell wall integrity. To gain insight into the role of individual genes of sphingolipid biosynthetic pathway, we have screened Saccharomyces cerevisiae strains deleted in these genes for sensitivity to cell wall perturbing agents calcofluor white and congo red. Only deletants of FEN1 and SUR4 genes were found to be sensitive to both these agents. Candida albicans strains deleted in their orthologs, CaFEN1 and CaFEN12, respectively, also showed comparable phenotypes, and a strain deleted for both these genes was extremely sensitive to cell wall perturbing agents. Deletion of these genes was reported earlier to sensitise cells to amphotericin B (AmB), which is a polyene drug that kills the cells mainly by binding and sequestering ergosterol from the plasma membrane. Here we show that their AmB sensitivity is likely due to their cell wall defect. Further, we show that double deletant of C. albicans is defective in hyphae formation as well as biofilm development. Together this study reveals that deletion of FEN1 and SUR4 orthologs of C. albicans leads to impaired cell wall integrity and biofilm formation, which in turn sensitise cells to AmB. PMID:28079132

  14. Water stress responses of tomato mutants impaired in hormone biosynthesis reveal abscisic acid, jasmonic acid and salicylic acid interactions

    Directory of Open Access Journals (Sweden)

    Valeria eMuñoz

    2015-11-01

    Full Text Available To investigate the putative crosstalk between JA and ABA in Solanum lycopersicum plants in response to drought, suppressor of prosystemin-mediated responses2 (spr2, JA-deficient and flacca (flc, ABA-deficient mutants together with the naphthalene/salicylate hydroxylase (NahG transgenic (SA-deficient line were used. Hormone profiling and gene expression of key enzymes in ABA, JA and SA biosynthesis were analyzed during early stages of drought. ABA accumulation was comparable in spr2 and wild type (WT plants whereas expression of 9-cis-epoxycarotenoid dioxygenase 1 (NCED1 and NCED2 was different, implying a compensation mechanism between NCED genes and an organ-specific regulation of NCED1 expression. JA levels and 12-oxo-phytodienoic acid reductase 3 (OPR3 expression in flc plants suggest that ABA regulates the induction of the OPR3 gene in roots. By contrast, ABA treatment to flc plants leads to a reduction of JA and SA contents. Furthermore, different pattern of SA accumulation (and expression of isochorismate synthase and phenylalanine ammonia lyase 1 was observed between WT seedlings and mutants, suggesting that SA plays an important role on the early response of tomato plants to drought and also that JA and ABA modulate its biosynthesis. Finally, hormone profiling in spr2 and NahG plants indicate a crosstalk between JA and SA that could enhance tolerance of tomato to water stress.

  15. Water Stress Responses of Tomato Mutants Impaired in Hormone Biosynthesis Reveal Abscisic Acid, Jasmonic Acid and Salicylic Acid Interactions

    Science.gov (United States)

    Muñoz-Espinoza, Valeria A.; López-Climent, María F.; Casaretto, José A.; Gómez-Cadenas, Aurelio

    2015-01-01

    To investigate the putative crosstalk between JA and ABA in Solanum lycopersicum plants in response to drought, suppressor of prosystemin-mediated responses2 (spr2, JA-deficient) and flacca (flc, ABA-deficient) mutants together with the naphthalene/salicylate hydroxylase (NahG) transgenic (SA-deficient) line were used. Hormone profiling and gene expression of key enzymes in ABA, JA and SA biosynthesis were analyzed during early stages of drought. ABA accumulation was comparable in spr2 and wild type (WT) plants whereas expression of 9-cis-epoxycarotenoid dioxygenase 1 (NCED1) and NCED2 was different, implying a compensation mechanism between NCED genes and an organ-specific regulation of NCED1 expression. JA levels and 12-oxo-phytodienoic acid reductase 3 (OPR3) expression in flc plants suggest that ABA regulates the induction of the OPR3 gene in roots. By contrast, ABA treatment to flc plants leads to a reduction of JA and SA contents. Furthermore, different pattern of SA accumulation (and expression of isochorismate synthase and phenylalanine ammonia lyase 1) was observed between WT seedlings and mutants, suggesting that SA plays an important role on the early response of tomato plants to drought and also that JA and ABA modulate its biosynthesis. Finally, hormone profiling in spr2 and NahG plants indicate a crosstalk between JA and SA that could enhance tolerance of tomato to water stress. PMID:26635826

  16. Metabolomic Analyses of Leishmania Reveal Multiple Species Differences and Large Differences in Amino Acid Metabolism.

    Directory of Open Access Journals (Sweden)

    Gareth D Westrop

    Full Text Available Comparative genomic analyses of Leishmania species have revealed relatively minor heterogeneity amongst recognised housekeeping genes and yet the species cause distinct infections and pathogenesis in their mammalian hosts. To gain greater information on the biochemical variation between species, and insights into possible metabolic mechanisms underpinning visceral and cutaneous leishmaniasis, we have undertaken in this study a comparative analysis of the metabolomes of promastigotes of L. donovani, L. major and L. mexicana. The analysis revealed 64 metabolites with confirmed identity differing 3-fold or more between the cell extracts of species, with 161 putatively identified metabolites differing similarly. Analysis of the media from cultures revealed an at least 3-fold difference in use or excretion of 43 metabolites of confirmed identity and 87 putatively identified metabolites that differed to a similar extent. Strikingly large differences were detected in their extent of amino acid use and metabolism, especially for tryptophan, aspartate, arginine and proline. Major pathways of tryptophan and arginine catabolism were shown to be to indole-3-lactate and arginic acid, respectively, which were excreted. The data presented provide clear evidence on the value of global metabolomic analyses in detecting species-specific metabolic features, thus application of this technology should be a major contributor to gaining greater understanding of how pathogens are adapted to infecting their hosts.

  17. Decreased eicosapentaenoic acid levels in acne vulgaris reveals the presence of a proinflammatory state.

    Science.gov (United States)

    Aslan, İbrahim; Özcan, Filiz; Karaarslan, Taner; Kıraç, Ebru; Aslan, Mutay

    2017-01-01

    This study aimed to determine circulating levels of polyunsaturated fatty acids (PUFAs), secretory phospholipase A2 (sPLA2), lipoprotein lipase (LPL) and measure circulating protein levels of angiopoietin-like protein 3 (ANGPTL3), ANGPTL4, cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) in patients with acne vulgaris. Serum from 21 control subjects and 31 acne vulgaris patients were evaluated for levels of arachidonic acid (AA, C20:4n- 6), dihomo-gamma-linolenic acid (DGLA, C20:3n-6), eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3). PUFA levels were determined by an optimized multiple reaction monitoring (MRM) method using ultra fast-liquid chromatography (UFLC) coupled with tandem mass spectrometry (MS/MS). Lipid profile, routine biochemical and hormone parameters were assayed by standard kit methods Serum EPA levels were significantly decreased while AA/EPA and DGLA/EPA ratio were significantly increased in acne vulgaris patients compared to controls. Serum levels of AA, DGLA and DHA showed no significant difference while activity of sPLA2 and LPL were significantly increased in acne vulgaris compared to controls. Results of this study reveal the presence of a proinflammatory state in acne vulgaris as shown by significantly decreased serum EPA levels and increased activity of sPLA2, AA/EPA and DGLA/EPA ratio. Increased LPL activity in the serum of acne vulgaris patients can be protective through its anti-dyslipidemic actions. This is the first study reporting altered EPA levels and increased sPLA2 activity in acne vulgaris and supports the use of omega-3 fatty acids as adjuvant treatment for acne patients.

  18. Modelling Seasonal Carbon Dynamics on Fen Peatlands

    Science.gov (United States)

    Giebels, Michael; Beyer, Madlen; Augustin, Jürgen; Roppel, Mario; Juszczak, Radoszlav; Serba, Tomasz

    2010-05-01

    In Germany more than 99 % of fens have lost their carbon and nutrient sink function due to heavy drainage and agricultural land use especially during the last decades and thus resulted in compression and heavy peat loss (CHARMAN 2002; JOOSTEN & CLARKE 2002; SUCCOW & JOOSTEN 2001; AUGUSTIN et al. 1996; KUNTZE 1993). Therefore fen peatlands play an important part (4-5 %) in the national anthropogenic trace gas budget. But only a small part of drained and agricultural used fens in NE Germany can be restored. Knowledge of the influence of land use to trace gas exchange is important for mitigation of the climate impact of the anthropogenic peatland use. We study carbon exchanges between soil and atmosphere on several fen peatland use areas at different sites in NE-Germany. Our research covers peatlands of supposed strongly climate forcing land use (cornfield and intensive pasture) and of probably less forcing, alternative types (meadow and extensive pasture) as well as rewetted (formerly drained) areas and near-natural sites like a low-degraded fen and a wetted alder woodland. We measured trace gas fluxes with manual and automatic chambers in periodic routines since spring 2007. The used chamber technique bases on DROESLER (2005). In total we now do research at 22 sites situated in 5 different locations covering agricultural, varying states of rewetted and near-natural treatments. We present results of at least 2 years of measurements on our site of varying types of agricultural land use. There we found significant differences in the annual carbon balances depending on the genesis of the observed sites and the seasonal dynamics. Annual balances were constructed by applying single respiration and photosynthesis CO2 models for each measurement campaign. These models were based on LLOYD-TAYLOR (1994) and Michaelis-Menten-Kinetics respectively. Crosswise comparison of different site treatments combined with the seasonal environmental observations give good hints for the

  19. [Acute fatty liver in pregnancy: revealing fetal fatty acid oxidation disorders].

    Science.gov (United States)

    Lamireau, D; Feghali, H; Redonnet-Vernhet, I; Mesli, S; Carles, D; Brissaud, O

    2012-03-01

    Acute fatty liver of pregnancy (AFLP) and hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome are serious maternal illnesses occurring in the third trimester of pregnancy with significant perinatal and maternal mortality. AFLP may result from mitochondrial defects in the beta-oxidation of fatty acids, in particular a deficiency of the long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) in the fetus. Clinical findings in AFLP vary and its diagnosis is complicated by a significant overlap in clinical and biochemical features with HELLP syndrome. We report the case of 2 siblings who died, the first one in the neonatal period of asphyxia with multivisceral presentation and the second one from sudden death at 7 months. Autopsy of the latter infant revealed hepatic steatosis associated with cardiomyopathy, which led to suspicion of a fatty acid oxidation deficiency. Mutation analysis demonstrated that both children were homozygous for the common mutation c.1528G>C and the parents were heterozygous for this same mutation. This case demonstrates the importance of screening mothers with acute fatty liver disease of pregnancy and their children at birth for a metabolic disease. This article proposes several metabolic tests for mother and child suspected of having beta-oxidation of a fatty acid disorder.

  20. Site directed mutagenesis of StSUT1 reveals target amino acids of regulation and stability.

    Science.gov (United States)

    Krügel, Undine; Wiederhold, Elena; Pustogowa, Jelena; Hackel, Aleksandra; Grimm, Bernhard; Kühn, Christina

    2013-11-01

    Plant sucrose transporters (SUTs) are functional as sucrose-proton-cotransporters with an optimal transport activity in the acidic pH range. Recently, the pH optimum of the Solanum tuberosum sucrose transporter StSUT1 was experimentally determined to range at an unexpectedly low pH of 3 or even below. Various research groups have confirmed these surprising findings independently and in different organisms. Here we provide further experimental evidence for a pH optimum at physiological extrema. Site directed mutagenesis provides information about functional amino acids, which are highly conserved and responsible for this extraordinary increase in transport capacity under extreme pH conditions. Redox-dependent dimerization of the StSUT1 protein was described earlier. Here the ability of StSUT1 to form homodimers was demonstrated by heterologous expression in Lactococcus lactis and Xenopus leavis using Western blots, and in plants by bimolecular fluorescence complementation. Mutagenesis of highly conserved cysteine residues revealed their importance in protein stability. The accessibility of regulatory amino acid residues in the light of StSUT1's compartmentalization in membrane microdomains is discussed.

  1. Efeito do tratamento térmico na concentração de carotenóides, compostos fenólicos, ácido ascórbico e capacidade antioxidante do suco de tangerina murcote Effect of thermal treatment on the carotenoid, phenolic compound and ascorbic acid concentrations, and the antioxidant capacity of murcott tangerine juice

    Directory of Open Access Journals (Sweden)

    André de Souza Dutra

    2012-09-01

    Full Text Available Neste estudo, avaliou-se o efeito do tratamento térmico do suco de tangerina murcote em relação ao teor de carotenóides totais, ao perfil de carotenóides (luteína, zeaxantina, β-criptoxantina e β-caroteno, aos compostos fenólicos totais, ao ácido ascórbico e à capacidade antioxidante. No processo, utilizou-se um trocador de calor tubular, sendo avaliados 11 tratamentos seguindo um ensaio fatorial completo 2² com três repetições no ponto central, com quatro pontos axiais e uma região de observação de 88 a 100 ºC e 16 a 44 s. O teor de caratenóides totais decresceu de forma significativa em quase todos os tratamentos aplicados, se comparado ao valor encontrado para o suco in natura. A maioria dos tratamentos não reduziu de forma significativa os teores dos caratenóides luteína, zeaxantina e β-criptoxantina. Além disso, o teor de β-caroteno não sofreu alterações significativas em todos os tratamentos avaliados. A análise de variância mostrou que, para os caratenóides, não ocorreram interações significativas entre as variáveis temperatura e tempo. Os teores de ácido ascórbico e compostos fenólicos totais apresentaram reduções em seis condições avaliadas, ao passo que, em quatro, observou-se um aumento dos teores de compostos fenólicos totais, causado provavelmente pela evaporação da água presente no suco. A maior redução do teor de ácido ascórbico e o maior aumento para compostos fenólicos totais foi observado para o binômio 100 ºC/30 s. O teor de ácido ascórbico sofreu de forma significativa a influência da temperatura e esse processo de degradação pode ser descrito por meio de um modelo quadrático. Todos os tratamentos utilizados reduziram a capacidade antioxidante do suco, sendo mais intensa para o binômio 100 ºC/30 s. As variações observadas não alteraram de maneira considerável as características nutricionais do suco e os tratamentos térmicos realizados a 94 ºC por 16 a 44 s

  2. From groundwater abstraction to vegetative response in fen ecosystems

    DEFF Research Database (Denmark)

    Johansen, Ole Munch; Jensen, Jacob Birk; Pedersen, Morten Lauge

    2014-01-01

    hydrology. Fens are rare and threatened worldwide due to pressures from agriculture, to lack of appropriate management and to altered catchment hydrology. A solid foundation for hydrological modelling was established based on intensive monitoring at the site, combined with full-scale pumping tests...... periods. The predicted change in water table conditions in the fen habitat is compared to the variability found in 35 Danish fens, and the ecological response is discussed based on statistical water-level vegetation relations. The results provide a rare quantitative foundation for decision making...... resolution. A considerable flow reduction in the natural spring was monitored during a full-scale pumping test while no significant effects on the water table in the fen habitats were observed. A modelled abstraction scenario predicted a lowering of 2–3 cm in the centre of the main fen area during summer...

  3. Omega-3 Fatty acids and inflammation: novel interactions reveal a new step in neutrophil recruitment.

    Directory of Open Access Journals (Sweden)

    Samantha P Tull

    2009-08-01

    Full Text Available Inflammation is a physiological response to tissue trauma or infection, but leukocytes, which are the effector cells of the inflammatory process, have powerful tissue remodelling capabilities. Thus, to ensure their precise localisation, passage of leukocytes from the blood into inflamed tissue is tightly regulated. Recruitment of blood borne neutrophils to the tissue stroma occurs during early inflammation. In this process, peptide agonists of the chemokine family are assumed to provide a chemotactic stimulus capable of supporting the migration of neutrophils across vascular endothelial cells, through the basement membrane of the vessel wall, and out into the tissue stroma. Here, we show that, although an initial chemokine stimulus is essential for the recruitment of flowing neutrophils by endothelial cells stimulated with the inflammatory cytokine tumour necrosis factor-alpha, transit of the endothelial monolayer is regulated by an additional and downstream stimulus. This signal is supplied by the metabolism of the omega-6-polyunsaturated fatty acid (n-6-PUFA, arachidonic acid, into the eicosanoid prostaglandin-D(2 (PGD(2 by cyclooxygenase (COX enzymes. This new step in the neutrophil recruitment process was revealed when the dietary n-3-PUFA, eicosapentaenoic acid (EPA, was utilised as an alternative substrate for COX enzymes, leading to the generation of PGD(3. This alternative series eicosanoid inhibited the migration of neutrophils across endothelial cells by antagonising the PGD(2 receptor. Here, we describe a new step in the neutrophil recruitment process that relies upon a lipid-mediated signal to regulate the migration of neutrophils across endothelial cells. PGD(2 signalling is subordinate to the chemokine-mediated activation of neutrophils, but without the sequential delivery of this signal, neutrophils fail to penetrate the endothelial cell monolayer. Importantly, the ability of the dietary n-3-PUFA, EPA, to inhibit this process not

  4. Polyploid genome of Camelina sativa revealed by isolation of fatty acid synthesis genes

    Directory of Open Access Journals (Sweden)

    Shewmaker Christine K

    2010-10-01

    Full Text Available Abstract Background Camelina sativa, an oilseed crop in the Brassicaceae family, has inspired renewed interest due to its potential for biofuels applications. Little is understood of the nature of the C. sativa genome, however. A study was undertaken to characterize two genes in the fatty acid biosynthesis pathway, fatty acid desaturase (FAD 2 and fatty acid elongase (FAE 1, which revealed unexpected complexity in the C. sativa genome. Results In C. sativa, Southern analysis indicates the presence of three copies of both FAD2 and FAE1 as well as LFY, a known single copy gene in other species. All three copies of both CsFAD2 and CsFAE1 are expressed in developing seeds, and sequence alignments show that previously described conserved sites are present, suggesting that all three copies of both genes could be functional. The regions downstream of CsFAD2 and upstream of CsFAE1 demonstrate co-linearity with the Arabidopsis genome. In addition, three expressed haplotypes were observed for six predicted single-copy genes in 454 sequencing analysis and results from flow cytometry indicate that the DNA content of C. sativa is approximately three-fold that of diploid Camelina relatives. Phylogenetic analyses further support a history of duplication and indicate that C. sativa and C. microcarpa might share a parental genome. Conclusions There is compelling evidence for triplication of the C. sativa genome, including a larger chromosome number and three-fold larger measured genome size than other Camelina relatives, three isolated copies of FAD2, FAE1, and the KCS17-FAE1 intergenic region, and three expressed haplotypes observed for six predicted single-copy genes. Based on these results, we propose that C. sativa be considered an allohexaploid. The characterization of fatty acid synthesis pathway genes will allow for the future manipulation of oil composition of this emerging biofuel crop; however, targeted manipulations of oil composition and general

  5. Fens as whole-ecosystem gauges of groundwater recharge under climate change

    Science.gov (United States)

    Drexler, Judith Z.; Knifong, Donna; Tuil, JayLee; Flint, Lorraine E.; Flint, Alan L.

    2013-02-01

    SummaryCurrently, little is known about the impact of climate change on groundwater recharge in the Sierra Nevada and southern Cascade Range of California or other mountainous regions of the world. The purpose of this study was to determine whether small alpine peatlands called fens can be used as whole-ecosystem gauges of groundwater recharge through time. Fens are sustained by groundwater discharge and are highly sensitive to changes in groundwater flow due to hydrologic disturbance including climate change. Seven fens in the Sierra Nevada and southern Cascade Range were studied over a 50-80 year period using historic aerial photography. In each aerial photograph, fen areas were identified as open lawn and partially treed areas that exhibited (1) dark brownish-green coloring or various shades of gray and black in black and white imagery and (2) mottling of colors and clustering of vegetation, which signified a distinct moss canopy with overlying clumped sedge vegetation. In addition to the aerial photography study, a climate analysis for the study sites was carried out using both measured data (U.S. Department of Agriculture Natural Resources Conservation Service SNOwpack TELemetry system) and modeled data (a downscaled version of the Parameter-elevation Regressions on Independent Slopes Model) for the period from 1951 to 2010. Over the study period, the five fens in the Sierra Nevada were found to be decreasing between 10% and 16% in delineated area. The climate analysis revealed significant increases through time in annual mean minimum temperature (Tmin) between 1951-1980 and 1981-2010. In addition, April 1 snow water equivalent and snowpack longevity also decreased between 1951-1980 and 1981-2010. For the fens in the Cascade Range, there were no discernible changes in delineated area. At these sites, increases in Tmin occurred only within the past 20-25 years and decreases in snowpack longevity were more subtle. A conceptual model is presented, which

  6. ‘Poor rich fen mosses’: atmospheric N-deposition and P-eutrophication in base-rich fens

    NARCIS (Netherlands)

    Kooijman, A.M.

    2012-01-01

    Base-rich fens in the Netherlands are threatened by acidification and replacement of rich-fen bryophytes by Sphagnum spp. Acidification is a natural process when input of base-rich water is reduced, and is probably accelerated by high atmospheric deposition, leading to lower pH at similar calcium le

  7. CO dissociation on magnetic Fen clusters

    KAUST Repository

    Jedidi, Abdesslem

    2014-01-01

    This work theoretically investigates the CO dissociation on Fen nanoparticles, for n in the range of 1-65, focusing on size dependence in the context of the initial step of the Fischer-Tropsch reaction. CO adsorbs molecularly through its C-end on a triangular facet of the nanoparticle. Dissociation becomes easier when the cluster size increases. Then, the C atom is bonded to a square facet that is generated as a result of the adsorption if it does not yet exist in the bare cluster, while the O atom is adsorbed on a triangular facet. In the most stable situation, the two adsorbed atoms remain close together, both having in common one shared first-neighbor iron atom. There is a partial spin quenching of the neighboring Fe atoms, which become more positively charged than the other Fe atoms. The shared surface iron atom resembles a metal-cation from a complex. Despite the small size of the iron cluster considered, fluctuations due to specific configurations do not influence properties for n > 25 and global trends seem significant.

  8. Short-Term Summer Inundation as a Measure to Counteract Acidification in Rich Fens.

    Directory of Open Access Journals (Sweden)

    Ivan S Mettrop

    Full Text Available In regions with intensive agriculture, water level fluctuation in wetlands has generally become constricted within narrow limits. Water authorities are, however, considering the re-establishment of fluctuating water levels as a management tool in biodiverse, base-rich fens ('rich fens'. This includes temporary inundation with surface water from ditches, which may play an important role in counteracting acidification in order to conserve and restore biodiversity. Inundation may result in an increased acid neutralizing capacity (ANC for two reasons: infiltration of base-rich inundation water into peat soils, and microbial alkalinity generation under anaerobic conditions. The main objectives of this study were to test whether short-term (2 weeks summer inundation is more effective than short-term winter inundation to restore the ANC in the upper 10 cm of non-floating peat soils, and to explain potential differences. Large-scale field experiments were conducted for five years in base-rich fens and Sphagnum-dominated poor fens. Winter inundation did not result in increased porewater ANC, because infiltration was inhibited in the waterlogged peat and evapotranspiration rates were relatively low. Also, low temperatures limit microbial alkalinity generation. In summer, however, when temperature and evapotranspiration rates are higher, inundation resulted in increased porewater Ca and HCO3- concentrations, but only in areas with characteristic rich fen bryophytes. This increase was not only due to stronger infiltration into the soil, but also to higher microbial alkalinity generation under anaerobic conditions. In contrast, porewater ANC did not increase in Sphagnum-plots as a result of the ability of Sphagnum spp. to acidify their environment. In both rich and poor fens, flooding-induced P-mobilization remained sufficiently low to safeguard P-limited vegetation. NO3(- and NH4(+ dynamics showed no considerable changes either. In conclusion, short

  9. Mollusc and plant assemblages controlled by different ecological gradients at Eastern European fens

    Science.gov (United States)

    Schenková, Veronika; Horsák, Michal; Hájek, Michal; Plesková, Zuzana; Dítě, Daniel; Pawlikowski, Paweł

    2014-04-01

    Ecological patterns of mollusc assemblages and vegetation in relation to water chemistry, water regime, nutrient availability and climate were studied in eastern Polish lowland fens. Our goal was to examine if major compositional changes differ for molluscs and vegetation under the joint influence of multiple ecological gradients. Altogether 32 fen sites were investigated in 2010-2011, and analyzed using metric multidimensional scaling, cluster analysis and generalized additive models. Two major gradients driving the differences in mollusc species composition were revealed. The main direction of compositional changes was associated with the water table gradient, governing a species turnover from inundated and strongly water-logged sites occupied mostly by aquatic mollusc species, to moderately wet sites with the predominance of fen and meadow species. The second most important gradient for molluscs was that of mineral richness. For vegetation, three major gradients explained the changes in species composition. The highest importance was assigned to the nitrogen-to-phosphorus availability gradient (defined as a shift from N-limited to P-limited vegetation), followed by the water table gradient, and the mineral richness gradient. Our results demonstrate that the impact of mineral richness gradient, which has been often reported as the major determinant of compositional changes of fen molluscs and vegetation, can be exceeded by other ecological gradients of comparable variation. We also document for the first time that the main species turnover of fen vegetation is not accompanied by the analogous change in species composition of mollusc assemblages, due to a different sensitivity of these taxa to particular environmental factors (i.e. water level dynamics and type of nutrient limitation).

  10. Microbial Response to Soil Liming of Damaged Ecosystems Revealed by Pyrosequencing and Phospholipid Fatty Acid Analyses

    Science.gov (United States)

    Narendrula-Kotha, Ramya; Nkongolo, Kabwe K.

    2017-01-01

    Aims To assess the effects of dolomitic limestone applications on soil microbial communities’ dynamics and bacterial and fungal biomass, relative abundance, and diversity in metal reclaimed regions. Methods and Results The study was conducted in reclaimed mining sites and metal uncontaminated areas. The limestone applications were performed over 35 years ago. Total microbial biomass was determined by Phospholipid fatty acids. Bacterial and fungal relative abundance and diversity were assessed using 454 pyrosequencing. There was a significant increase of total microbial biomass in limed sites (342 ng/g) compared to unlimed areas (149 ng/g). Chao1 estimates followed the same trend. But the total number of OTUs (Operational Taxonomic Units) in limed (463 OTUs) and unlimed (473 OTUs) soil samples for bacteria were similar. For fungi, OTUs were 96 and 81 for limed and unlimed soil samples, respectively. Likewise, Simpson and Shannon diversity indices revealed no significant differences between limed and unlimed sites. Bacterial and fungal groups specific to either limed or unlimed sites were identified. Five major bacterial phyla including Actinobacteria, Acidobacteria, Chloroflexi, Firmicutes, and Proteobacteria were found. The latter was the most prevalent phylum in all the samples with a relative abundance of 50%. Bradyrhizobiaceae family with 12 genera including the nitrogen fixing Bradirhizobium genus was more abundant in limed sites compared to unlimed areas. For fungi, Ascomycota was the most predominant phylum in unlimed soils (46%) while Basidiomycota phylum represented 86% of all fungi in the limed areas. Conclusion Detailed analysis of the data revealed that although soil liming increases significantly the amount of microbial biomass, the level of species diversity remain statistically unchanged even though the microbial compositions of the damaged and restored sites are different. Significance and Impact of the study Soil liming still have a significant

  11. Exploratory investigation reveals parallel alteration of plasma fatty acids and eicosanoids in coronary artery disease patients.

    Science.gov (United States)

    Xu, Yong-Jiang; Ho, Wanxing Eugene; Xu, Fengguo; Wen, Tao; Ong, Choon Nam

    2013-10-01

    Fatty acids and eicosanoids are two important classes of signaling lipid molecules involved in the pathogenesis of cardiovascular diseases. To investigate the physiological functions and interplay between fatty acids and eicosanoids in coronary artery disease (CAD) patients, we developed an analytical approach for parallel quantitative analysis of plasma fatty acids and eicosanoids, using gas chromatography-tandem mass spectrometry (GC-MS/MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this study, 26 fatty acids and 12 eicosanoids were confidently detected in 12 patients with confirmed coronary artery disease and 11 healthy subjects. Pattern recognition analysis (principal components analysis, orthogonal partial least-square discriminate analysis, and hierarchical clustering analysis) demonstrated that the plasma lipid profile of fatty acids and eicosanoids enabled robust discrimination of CAD patients versus healthy subjects. Significant differences in six fatty acids and five eicosanoids were noted among CAD patients and healthy subjects. The development of cardiovascular disease-induced metabolic change of fatty acids and eicosanoids, such as eicosapentaenoic acid, docosahexaenoic acid, arachidonic acid, hydroxyeicosatetraenoic acids and hydroxyoctadecadienoic acid, were consistent with previous isolated observations. Moderate-strong correlations between three plasma fatty acids and three eicosanoids from arachidonic acid metabolism were also observed. In brief, findings from this exploratory study offered a new insight on the roles of various bioactive lipid molecules in the development of coronary artery disease biomarkers.

  12. Lipidomic profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii reveals critical changes in lipid composition in response to acetic acid stress.

    Science.gov (United States)

    Lindberg, Lina; Santos, Aline Xs; Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

    2013-01-01

    When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large

  13. Lipidomic profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii reveals critical changes in lipid composition in response to acetic acid stress.

    Directory of Open Access Journals (Sweden)

    Lina Lindberg

    Full Text Available When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D and Zygosaccharomyces bailii (CBS7555 cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1, while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1 acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP2C 2.2× and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP2C 2.7×, when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to

  14. Dietary supplementation with arachidonic acid in tilapia (Oreochromis mossambicus) reveals physiological effects not mediated by prostaglandins.

    NARCIS (Netherlands)

    Anholt, R.D. van; Spanings, F.A.T.; Koven, W.M.; Wendelaar Bonga, S.E.

    2004-01-01

    This study aims to clarify the role of the polyunsaturated fatty acid arachidonic acid (ArA, 20:4n-6) in the stress response of Mozambique tilapia (Oreochromis mossambicus). ArA is converted into eicosanoids, including prostaglandins, which can influence the response to stressors. Tilapia, a species

  15. Characterization of Fen-Daqu Through Multivariate Statistical Analysis of H-1 NMR Spectroscopic Data

    NARCIS (Netherlands)

    Van-Diep, L.; Zheng, X.; Ma, K.; Chen, J.Y.; Han, B.Z.; Nout, M.J.R.

    2011-01-01

    J. Inst. Brew. 117(4), 516-522, 2011 Fen liquor is typical of Chinese light-flavour liquor (alcoholic spirit), which is fermented from sorghum with Fen-Daqu powder. Fen-Daqu is a saccharifying agent and fermentation starter in this fermentation process and in Fen traditional vinegar. To investigate

  16. Structure of the Cyanuric Acid Hydrolase TrzD Reveals Product Exit Channel

    Energy Technology Data Exchange (ETDEWEB)

    Bera, Asim K.; Aukema, Kelly G.; Elias, Mikael; Wackett, Lawrence P.

    2017-03-27

    Cyanuric acid hydrolases are of industrial importance because of their use in aquatic recreational facilities to remove cyanuric acid, a stabilizer for the chlorine. Degradation of excess cyanuric acid is necessary to maintain chlorine disinfection in the waters. Cyanuric acid hydrolase opens the cyanuric acid ring hydrolytically and subsequent decarboxylation produces carbon dioxide and biuret. In the present study, we report the X-ray structure of TrzD, a cyanuric acid hydrolase from Acidovorax citrulli. The crystal structure at 2.19 Å resolution shows a large displacement of the catalytic lysine (Lys163) in domain 2 away from the active site core, whereas the two other active site lysines from the two other domains are not able to move. The lysine displacement is proposed here to open up a channel for product release. Consistent with that, the structure also showed two molecules of the co-product, carbon dioxide, one in the active site and another trapped in the proposed exit channel. Previous data indicated that the domain 2 lysine residue plays a role in activating an adjacent serine residue carrying out nucleophilic attack, opening the cyanuric acid ring, and the mobile lysine guides products through the exit channel.

  17. Effect of Pre-Stressing on the Acid-Stress Response in Bifidobacterium Revealed Using Proteomic and Physiological Approaches.

    Directory of Open Access Journals (Sweden)

    Junhua Jin

    Full Text Available Weak acid resistance limits the application of Bifidobacteria as a probiotic in food. The acid tolerance response (ATR, caused by pre-stressing cells at a sublethal pH, could improve the acid resistance of Bifidobacteria to subsequent acid stress. In this study, we used Bifidobacterium longum sub. longum BBMN68 to investigate the effect of the ATR on the acid stress response (ASR, and compared the difference between the ATR and the ASR by analyzing the two-dimensional-PAGE protein profiles and performing physiological tests. The results revealed that a greater abundance of proteins involved in carbohydrate metabolism and protein protection was present after the ASR than after the ATR in Bifidobacterium. Pre-stressing cells increased the abundance of proteins involved in energy production, amino acid metabolism, and peptidoglycan synthesis during the ASR of Bifidobacterium. Moreover, after the ASR, the content of ATP, NH3, thiols, and peptidoglycan, the activity of H+-ATPase, and the maintenance of the intracellular pH in the pre-stressed Bifidobacterium cells was significantly higher than in the uninduced cells. These results provide the first explanation as to why the resistance of Bifidobacterium to acid stress improved after pre-stressing.

  18. Revealing the Mechanistic Pathway of Acid Activation of Proton Pump Inhibitors To Inhibit the Gastric Proton Pump: A DFT Study.

    Science.gov (United States)

    Jana, Kalyanashis; Bandyopadhyay, Tusar; Ganguly, Bishwajit

    2016-12-29

    Acid-related gastric diseases are associated with disorder of digestive tract acidification due to the acid secretion by gastric proton pump, H(+),K(+)-ATPase. Omeprazole is one of the persuasive irreversible inhibitor of the proton pump H(+),K(+)-ATPase. However, the reports on the mechanistic pathway of irreversible proton pump inhibitors (PPIs) on the acid activation and formation of disulfide complex are scarce in the literature. We have examined the acid activation PPIs, i.e., timoprazole, S-omeprazole and R-omeprazole using M062X/6-31++G(d,p) in aqueous phase with SMD solvation model. The proton pump inhibitor is a prodrug and activated in the acidic canaliculi of the gastric pump H(+),K(+)-ATPase to sulfenic acid which can either form another acid activate intermediate sulfenamide or a disulfide complex with cysteine amino acid of H(+),K(+)-ATPase. The quantum chemical calculations suggest that the transition state (TS5) for the disulfide complex formation is the rate-determining step of the multistep acid inhibition process by PPIs. The free energy barrier of TS5 is 5.5 kcal/mol higher for timoprazole compared to the S-omeprazole. The stability of the transition state for the formation of disulfide bond between S-omeprazole and cysteine amino acid of H(+),K(+)-ATPase is governed by inter- and intramolecular hydrogen bonding. The disulfide complex for S-omeprazole is thermodynamically more stable by 4.5 kcal/mol in aqueous phase compared to disulfide complex of timoprazole, which corroborates the less efficacy of timoprazole as irreversible PPI for acid inhibition process. It has been speculated that sulfenic acid can either form sulfenamide or a stable disulfide complex with cysteine amino acid residue of H(+),K(+)-ATPase. The M062X/6-31++G(d,p) level of theory calculated results reveal that the formation of tetra cyclic sulfenamide is unfavored by ∼17 kcal/mol for S-omeprazole and 11.5 kcal/mol for timoprazole compared to the disulfide complex formation

  19. Metabolomics reveals amino acids contribute to variation in response to simvastatin treatment.

    Directory of Open Access Journals (Sweden)

    Miles Trupp

    Full Text Available UNLABELLED: Statins are widely prescribed for reducing LDL-cholesterol (C and risk for cardiovascular disease (CVD, but there is considerable variation in therapeutic response. We used a gas chromatography-time-of-flight mass-spectrometry-based metabolomics platform to evaluate global effects of simvastatin on intermediary metabolism. Analyses were conducted in 148 participants in the Cholesterol and Pharmacogenetics study who were profiled pre and six weeks post treatment with 40 mg/day simvastatin: 100 randomly selected from the full range of the LDL-C response distribution and 24 each from the top and bottom 10% of this distribution ("good" and "poor" responders, respectively. The metabolic signature of drug exposure in the full range of responders included essential amino acids, lauric acid (p<0.0055, q<0.055, and alpha-tocopherol (p<0.0003, q<0.017. Using the HumanCyc database and pathway enrichment analysis, we observed that the metabolites of drug exposure were enriched for the pathway class amino acid degradation (p<0.0032. Metabolites whose change correlated with LDL-C lowering response to simvastatin in the full range responders included cystine, urea cycle intermediates, and the dibasic amino acids ornithine, citrulline and lysine. These dibasic amino acids share plasma membrane transporters with arginine, the rate-limiting substrate for nitric oxide synthase (NOS, a critical mediator of cardiovascular health. Baseline metabolic profiles of the good and poor responders were analyzed by orthogonal partial least square discriminant analysis so as to determine the metabolites that best separated the two response groups and could be predictive of LDL-C response. Among these were xanthine, 2-hydroxyvaleric acid, succinic acid, stearic acid, and fructose. Together, the findings from this study indicate that clusters of metabolites involved in multiple pathways not directly connected with cholesterol metabolism may play a role in modulating

  20. Global metabolomic profiling reveals an association of metal fume exposure and plasma unsaturated fatty acids.

    Directory of Open Access Journals (Sweden)

    Yongyue Wei

    Full Text Available BACKGROUND: Welding-associated air pollutants negatively affect the health of exposed workers; however, their molecular mechanisms in causing disease remain largely unclear. Few studies have systematically investigated the systemic toxic effects of welding fumes on humans. OBJECTIVES: To explore the effects of welding fumes on the plasma metabolome, and to identify biomarkers for risk assessment of welding fume exposure. METHODS: The two-stage, self-controlled exploratory study included 11 boilermakers from a 2011 discovery panel and 8 boilermakers from a 2012 validation panel. Plasma samples were collected pre- and post-welding fume exposure and analyzed by chromatography/mass spectrometry. RESULTS: Eicosapentaenoic or docosapentaenoic acid metabolic changes post-welding were significantly associated with particulate (PM2.5 exposure (p<0.05. The combined analysis by linear mixed-effects model showed that exposure was associated with a statistically significant decline in metabolite change of eicosapentaenoic acid [β(95% CI = -0.013(-0.022 ≈ -0.004; p = 0.005], docosapentaenoic acid n3 [β(95% CI = -0.010(-0.018 ≈ -0.002; p = 0.017], and docosapentaenoic acid n6 [β(95% CI = -0.007(-0.013 ≈ -0.001; p = 0.021]. Pathway analysis identified an association of the unsaturated fatty acid pathway with exposure (p Study-2011 = 0.025; p Study-2012 = 0.021; p Combined = 0.009. The functional network built by these fatty acids and their interactive genes contained significant enrichment of genes associated with various diseases, including neoplasms, cardiovascular diseases, and lipid metabolism disorders. CONCLUSIONS: High-dose exposure of metal welding fumes decreases unsaturated fatty acids with an exposure-response relationship. This alteration in fatty acids is a potential biological mediator and biomarker for exposure-related health disorders.

  1. Warming increases isoprene emissions from an arctic fen.

    Science.gov (United States)

    Lindwall, Frida; Svendsen, Sophie Sylvest; Nielsen, Cecilie Skov; Michelsen, Anders; Rinnan, Riikka

    2016-05-15

    Emissions of biogenic volatile organic compounds (BVOCs) from dry ecosystems at high latitudes respond strongly to small increases in temperature, and warm canopy surface temperatures drive emissions to higher levels than expected. However, it is not known whether emissions from wetlands, cooled by through-flowing water and higher evapotranspiration show similar response to warming as in drier ecosystems. Climate change will cause parts of the Arctic to experience increased snow fall, which delays the start of the growing season, insulates soil from low temperatures in winter, and increases soil moisture and possibly nutrient availability. Currently the effects of increasing snow depth on BVOC emissions are unknown. BVOC emissions were measured in situ across the growing season in a climate experiment, which used open top chambers to increase temperature and snow fences to increase winter snow depth. The treatments were arranged in a full factorial design. Measurements took place during two growing seasons in a fen ecosystem in west Greenland. BVOC samples collected by an enclosure technique in adsorbent cartridges were analysed using gas chromatography-mass spectrometry. Gross ecosystem production (GEP) was measured with a closed chamber technique, to reveal any immediate effect of treatments on photosynthesis, which could further influence BVOC emissions. Isoprene made up 84-92% of the emitted BVOCs. Isoprene emission increased 240 and 340% due to an increase in temperature of 1.3 and 1.6°C in 2014 and 2015, respectively. Isoprene emissions were 25 times higher in 2015 than in 2014 most likely due to a 2.4°C higher canopy air temperature during sampling in 2015. Snow addition had no significant effect on isoprene emissions even though GEP was increased by 24%. Arctic BVOC emissions respond strongly to rising temperatures in wet ecosystems, suggesting a large increase in arctic emissions in a future warmer climate.

  2. Ácidos fenólicos como antioxidantes

    OpenAIRE

    Soares,Sergio Eduardo

    2002-01-01

    Os compostos fenólicos têm sido muito estudados devido a sua influência na qualidade dos alimentos. Englobam uma gama enorme de substâncias, entre elas os ácidos fenólicos, os quais, por sua constituição química, possuem propriedades antioxidantes. Assim, a presente revisão procura reunir diversos estudos que avaliaram o potencial antioxidante dos ácidos fenólicos na conservação de alimentos lipídicos. Além disso, são reunidos também estudos sobre a ação antioxidante destes compostos no siste...

  3. Tertiary structure of human alpha1-acid glycoprotein (orosomucoid). Straightforward fluorescence experiments revealing the presence of a binding pocket.

    Science.gov (United States)

    Albani, Jihad R

    2004-02-25

    Binding of hemin to alpha1-acid glycoprotein has been investigated. Hemin binds to the hydrophobic pocket of hemoproteins. The fluorescent probe 2-(p-toluidino)-6-naphthalenesulfonate (TNS) binds to a hydrophobic domain in alpha1-acid glycoprotein with a dissociation constant equal to 60 microM. Addition of hemin to an alpha1-acid glycoprotein-TNS complex induces the displacement of TNS from its binding site. At saturation (1 hemin for 1 protein) all the TNS has been displaced from its binding site. The dissociation constant of hemin-alpha1-acid glycoprotein was found equal to 2 microM. Thus, TNS and hemin bind to the same hydrophobic site: the pocket of alpha1-acid glycoprotein. Energy-transfer studies performed between the Trp residues of alpha1-acid glycoprotein and hemin indicated that efficiency (E) of Trp fluorescence quenching was equal to 80% and the Förster distance, R0 at which the efficiency of energy transfer is 50% was calculated to be 26 A, revealing a very high energy transfer.

  4. Proteomics-based metabolic modeling reveals that fatty acid oxidation (FAO) controls endothelial cell (EC) permeability.

    Science.gov (United States)

    Patella, Francesca; Schug, Zachary T; Persi, Erez; Neilson, Lisa J; Erami, Zahra; Avanzato, Daniele; Maione, Federica; Hernandez-Fernaud, Juan R; Mackay, Gillian; Zheng, Liang; Reid, Steven; Frezza, Christian; Giraudo, Enrico; Fiorio Pla, Alessandra; Anderson, Kurt; Ruppin, Eytan; Gottlieb, Eyal; Zanivan, Sara

    2015-03-01

    Endothelial cells (ECs) play a key role to maintain the functionality of blood vessels. Altered EC permeability causes severe impairment in vessel stability and is a hallmark of pathologies such as cancer and thrombosis. Integrating label-free quantitative proteomics data into genome-wide metabolic modeling, we built up a model that predicts the metabolic fluxes in ECs when cultured on a tridimensional matrix and organize into a vascular-like network. We discovered how fatty acid oxidation increases when ECs are assembled into a fully formed network that can be disrupted by inhibiting CPT1A, the fatty acid oxidation rate-limiting enzyme. Acute CPT1A inhibition reduces cellular ATP levels and oxygen consumption, which are restored by replenishing the tricarboxylic acid cycle. Remarkably, global phosphoproteomic changes measured upon acute CPT1A inhibition pinpointed altered calcium signaling. Indeed, CPT1A inhibition increases intracellular calcium oscillations. Finally, inhibiting CPT1A induces hyperpermeability in vitro and leakage of blood vessel in vivo, which were restored blocking calcium influx or replenishing the tricarboxylic acid cycle. Fatty acid oxidation emerges as central regulator of endothelial functions and blood vessel stability and druggable pathway to control pathological vascular permeability.

  5. Deciphering Carbamoylpolyoxamic Acid Biosynthesis Reveals Unusual Acetylation Cycle Associated with Tandem Reduction and Sequential Hydroxylation.

    Science.gov (United States)

    Qi, Jianzhao; Wan, Dan; Ma, Hongmin; Liu, Yuanzhen; Gong, Rong; Qu, Xudong; Sun, Yuhui; Deng, Zixin; Chen, Wenqing

    2016-08-18

    Polyoxin, produced by Streptomcyes cacaoi var. asoensis and Streptomyces aureochromogenes, contains two non-proteinogenic amino acids, carbamoylpolyoxamic acid (CPOAA) and polyoximic acid. Although the CPOAA moiety is highly unusual, its biosynthetic logic has remained enigmatic for decades. Here, we address CPOAA biosynthesis by reconstitution of its pathway. We demonstrated that its biosynthesis is initiated by a versatile N-acetyltransferase, PolN, catalyzing L-glutamate (1) to N-acetyl glutamate (2). Remarkably, we verified that PolM, a previously annotated dehydrogenase, catalyzes an unprecedented tandem reduction of acyl-phosphate to aldehyde, and subsequently to alcohol. We also unveiled a distinctive acetylation cycle catalyzed by PolN to synthesize α-amino-δ-hydroxyvaleric acid (6). Finally, we report that PolL is capable of converting a rare sequential hydroxylation of α-amino-δ-carbamoylhydroxyvaleric acid (7) to CPOAA. PolL represents an intriguing family of Fe(II)-dependent α-ketoglutarate dioxygenase with a cupin fold. These data illustrate several novel enzymatic reactions, and also set a foundation for rational pathway engineering for polyoxin production.

  6. Proteomics-Based Metabolic Modeling Reveals That Fatty Acid Oxidation (FAO) Controls Endothelial Cell (EC) Permeability*

    Science.gov (United States)

    Patella, Francesca; Schug, Zachary T.; Persi, Erez; Neilson, Lisa J.; Erami, Zahra; Avanzato, Daniele; Maione, Federica; Hernandez-Fernaud, Juan R.; Mackay, Gillian; Zheng, Liang; Reid, Steven; Frezza, Christian; Giraudo, Enrico; Fiorio Pla, Alessandra; Anderson, Kurt; Ruppin, Eytan; Gottlieb, Eyal; Zanivan, Sara

    2015-01-01

    Endothelial cells (ECs) play a key role to maintain the functionality of blood vessels. Altered EC permeability causes severe impairment in vessel stability and is a hallmark of pathologies such as cancer and thrombosis. Integrating label-free quantitative proteomics data into genome-wide metabolic modeling, we built up a model that predicts the metabolic fluxes in ECs when cultured on a tridimensional matrix and organize into a vascular-like network. We discovered how fatty acid oxidation increases when ECs are assembled into a fully formed network that can be disrupted by inhibiting CPT1A, the fatty acid oxidation rate-limiting enzyme. Acute CPT1A inhibition reduces cellular ATP levels and oxygen consumption, which are restored by replenishing the tricarboxylic acid cycle. Remarkably, global phosphoproteomic changes measured upon acute CPT1A inhibition pinpointed altered calcium signaling. Indeed, CPT1A inhibition increases intracellular calcium oscillations. Finally, inhibiting CPT1A induces hyperpermeability in vitro and leakage of blood vessel in vivo, which were restored blocking calcium influx or replenishing the tricarboxylic acid cycle. Fatty acid oxidation emerges as central regulator of endothelial functions and blood vessel stability and druggable pathway to control pathological vascular permeability. PMID:25573745

  7. Comparative Transcriptomics Reveals Discrete Survival Responses of S. aureus and S. epidermidis to Sapienic Acid

    Science.gov (United States)

    Moran, Josephine C.; Alorabi, Jamal A.; Horsburgh, Malcolm J.

    2017-01-01

    Staphylococcal colonization of human skin is ubiquitous, with particular species more frequent at different body sites. Whereas Staphylococcus epidermidis can be isolated from the skin of every individual tested, Staphylococcus aureus is isolated from arginine deiminase, the oxygen-responsive NreABC nitrogen regulation system and the nitrate and nitrite reduction pathways. The role of S. aureus ACME and chromosomal arginine deiminase pathways in sapienic acid resistance was determined through mutational studies. We speculate that ammonia production could contribute to sapienic acid resistance in staphylococci. PMID:28179897

  8. Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites

    OpenAIRE

    Zahid, Henna; Miah, Layeque; Lau, Andy; Brochard, Lea; Hati, Debolina; Bui, T. T.; Drake, A. F.; Gor, Jayesh; Perkins, Stephen J.; McDermott, Lindsay C.

    2016-01-01

    Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigate...

  9. Fenómeno de Koebner The Koebner phenomenon

    OpenAIRE

    R E Achenbach

    2011-01-01

    Descrito en 1871 por Heinrich Koebner, su fenómeno es uno de los más conocidos en la Dermatología. Koebner lo describe en un paciente con psoriasis que sufrió escoriaciones múltiples y una mordedura de caballo. Su figura fue una de las más destacadas en la Dermatología del siglo 19. Se revisa la lista de entidades con fenómeno Koebner y sus variantes, los tipos de injurias y su patogenia.First described in 1871, the Koebner phenomenon is one of the most well-known entities in dermatology. Hei...

  10. CAPSAICIN AND ASCORBIC ACID VARIABILITY IN CHILLI AND PAPRIKA CULTIVARS AS REVEALED BY HPLC ANALYSIS

    Directory of Open Access Journals (Sweden)

    Samuel Tilahun

    2013-10-01

    Full Text Available Capsaicin and ascorbic acid contents of seven Indian peppers varieties/accessions from Capsicum annuum (CA 97, CCH, K1, KTPL19, Arka Abhir and Bayadagi Kaddi and C. frutescens (CF1 species were determined using High Performance Liquid Chromatography (HPLC. Based on their pungency value, all the chilli accession/varieties (CA 97, CCH, K1, and CF 1 were classified as highly pungent peppers. The accession CF1 showed the highest concentration of capsaicin (445mg 100g -1 DW with corresponding pungency value of 71,200 SHUs and Arka Abhir variety showed the lowest capsaicin concentration (29mg 100g -1 DW with 4,672 SHUs of pungency value. Similarly, Bayadaggi kaddi variety showed the highest ascorbic acid content (189 mg/100 FW and the accession CA 97 showed the lowest ascorbic acid contents (55.3 mg/100 FW. The variability in capsaicin and ascorbic acid content presented in the pepper germplasm can be exploited for breeding cultivars with improved nutritional qualities. Moreover, CF1and Bayadagi kaddi can be used as a potential source for capsaicin and vitamin C, respectively.

  11. CAPSAICIN AND ASCORBIC ACID VARIABILITY IN CHILLI AND PAPRIKA CULTIVARS AS REVEALED BY HPLC ANALYSIS

    Directory of Open Access Journals (Sweden)

    Samuel Tilahun

    2013-08-01

    Full Text Available Capsaicin and ascorbic acid contents of seven Indian peppers varieties/accessions from Capsicum annuum (CA 97, CCH, K1, KTPL19, Arka Abhir and Bayadagi Kaddi and C. frutescens (CF1 species were determined using High Performance Liquid Chromatography (HPLC. Based on their pungency value, all the chilli accession/varieties (CA 97, CCH, K1, and CF 1 were classified as highly pungent peppers. The accession CF1 showed the highest concentration of capsaicin (445mg 100g -1 DW with corresponding pungency value of 71,200 SHUs and Arka Abhir variety showed the lowest capsaicin concentration (29mg 100g -1 DW with 4,672 SHUs of pungency value. Similarly, Bayadaggi kaddi variety showed the highest ascorbic acid content (189 mg/100 FW and the accession CA 97 showed the lowest ascorbic acid contents (55.3 mg/100 FW. The variability in capsaicin and ascorbic acid content presented in the pepper germplasm can be exploited for breeding cultivars with improved nutritional qualities. Moreover, CF1and Bayadagi kaddi can be used as a potential source for capsaicin and vitamin C, respectively.

  12. A chemical perspective on transcriptional fidelity dominant contributions of sugar integrity revealed by unlocked nucleic acids

    DEFF Research Database (Denmark)

    Xu, Liang; Plouffe, Steven W; Chong, Jenny;

    2013-01-01

    Transcription unlocked: A synthetic chemical biology approach involving unlocked nucleic acids was used to dissect the contribution of sugar backbone integrity to the RNA Polymerase II (Pol II) transcription process. An unexpected dominant role for sugar-ring integrity in Pol II transcriptional...

  13. Revealing the compact structure of lactic acid bacterial hetero-exopolysaccharides by SAXS and DLS

    DEFF Research Database (Denmark)

    Khan, Sanaullah; Birch, Johnny; Harris, Pernille

    2017-01-01

    solution structures of three lactic acid bacterial hetero-exopolysaccharides (HePS-1, HePS-2 and HePS-3). Values of radius of gyration RG, cross-sectional radius of gyration RXS, approximate length L and hydrodynamic diameter were not directly proportional to the molar mass and indicated the HePSs adopted...

  14. Antagonists of chemoattractants reveal separate receptors for cAMP, folic acid and pterin in Dictyostelium

    NARCIS (Netherlands)

    Haastert, Peter J.M. van; Wit, René J.W. de; Konijn, Theo M.

    1982-01-01

    Adenosine 3’,5’-monophosphate (cAMP), folic acid and pterin are chemoattractants in the cellular slime molds. The cAMP analog, 3’-amino-cAMP, inhibits a chemotactic reaction to cAMP at a concentration at which the analog is chemotactically inactive. The antagonistic effect of 3’-amino-cAMP on the ch

  15. Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites.

    Science.gov (United States)

    Zahid, Henna; Miah, Layeque; Lau, Andy M; Brochard, Lea; Hati, Debolina; Bui, Tam T T; Drake, Alex F; Gor, Jayesh; Perkins, Stephen J; McDermott, Lindsay C

    2016-01-01

    Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigated. Analytical ultracentrifugation (AUC) and CD showed that zinc, but not other divalent metals, causes ZAG to oligomerize in solution. Thus ZAG dimers and trimers were observed in the presence of 1 and 2 mM zinc. Molecular modelling of X-ray scattering curves and sedimentation coefficients indicated a progressive stacking of ZAG monomers, suggesting that the ZAG groove may be occluded in these. Using fluorescence-detected sedimentation velocity, these ZAG-zinc oligomers were again observed in the presence of the fluorescent boron dipyrromethene fatty acid C16-BODIPY (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-hexadecanoic acid). Fluorescence spectroscopy confirmed that ZAG binds C16-BODIPY. ZAG binding to C16-BODIPY, but not to DAUDA, was reduced by increased zinc concentrations. We conclude that the lipid-binding groove in ZAG contains at least two distinct fatty acid-binding sites for DAUDA and C16-BODIPY, similar to the multiple lipid binding seen in the structurally related immune protein CD1c. In addition, because high concentrations of zinc occur in the pancreas, the perturbation of these multiple lipid-binding sites by zinc may be significant in Type 2 diabetes where dysregulation of ZAG and zinc homoeostasis occurs.

  16. Six Tissue Transcriptomics Reveals Specific Immune Suppression in Spleen by Dietary Polyunsaturated Fatty Acids.

    Directory of Open Access Journals (Sweden)

    Sara L Svahn

    Full Text Available Dietary polyunsaturated fatty acids (PUFA are suggested to modulate immune function, but the effects of dietary fatty acids composition on gene expression patterns in immune organs have not been fully characterized. In the current study we investigated how dietary fatty acids composition affects the total transcriptome profile, and especially, immune related genes in two immune organs, spleen (SPL and bone marrow cells (BMC. Four tissues with metabolic function, skeletal muscle (SKM, white adipose tissue (WAT, brown adipose tissue (BAT, and liver (LIV, were investigated as a comparison. Following 8 weeks on low fat diet (LFD, high fat diet (HFD rich in saturated fatty acids (HFD-S, or HFD rich in PUFA (HFD-P, tissue transcriptomics were analyzed by microarray and metabolic health assessed by fasting blood glucose level, HOMA-IR index, oral glucose tolerance test as well as quantification of crown-like structures in WAT. HFD-P corrected the metabolic phenotype induced by HFD-S. Interestingly, SKM and BMC were relatively inert to the diets, whereas the two adipose tissues (WAT and BAT were mainly affected by HFD per se (both HFD-S and HFD-P. In particular, WAT gene expression was driven closer to that of the immune organs SPL and BMC by HFDs. The LIV exhibited different responses to both of the HFDs. Surprisingly, the spleen showed a major response to HFD-P (82 genes differed from LFD, mostly immune genes, while it was not affected at all by HFD-S (0 genes differed from LFD. In conclusion, the quantity and composition of dietary fatty acids affected the transcriptome in distinct manners in different organs. Remarkably, dietary PUFA, but not saturated fat, prompted a specific regulation of immune related genes in the spleen, opening the possibility that PUFA can regulate immune function by influencing gene expression in this organ.

  17. Fenólicos totais e capacidade antioxidante in vitro de polpas de frutos tropicais

    Directory of Open Access Journals (Sweden)

    Luanne Morais Vieira

    2011-09-01

    Full Text Available O consumo de frutos e suas polpas tem sido muito recomendado por seu valor nutricional, alto teor de fibras, vitamina C e carotenoides. Trabalhos recentes têm apontado esses alimentos como fontes de compostos fenólicos com ação antioxidante, portanto sequestradores de radicais livres, com ação protetora contra o surgimento e/ou desenvolvimento de processos degenerativos que conduzem a doenças crônicas não transmissíveis. Devido à crescente comercialização e consumo de polpas de frutas no Brasil, especialmente na cidade de Teresina-Piauí, este trabalho selecionou um grupo de polpas de frutos de elevado consumo local para avaliação do teor de fenólicos totais e da atividade antioxidante in vitro pelo método de captura de radicais livres: DPPH (radical 1,1-diphenil-2-picrilhydrazil e ABTS (radical 2,2'azinobis(3-ethylbenzthiazoline-6-sulfonic acid. Os frutos selecionados foram: Acerola (Malpighia emarginata DC., Bacuri (Platonia insignis Mart., Cajá (Spondias mombin L., Caju (Anacardium occidentale, Goiaba(Psidium guajava e Tamarindo (Tamarindus indica L.. Os teores de fenólicos totais encontrados nas polpascongeladas destes frutos exibiram quantidades relevantes de polifenóis, destacando-se a polpa de acerola com 835,25 ± 32,44 e 449,63 ± 10,24 mg /100g nos extratos aquosos e hidroalcoólicos, respectivamente, seguido pela polpa de caju com 201,61 ± 19,15 e 165,07 ± 4,10 mg /100g. As polpas de bacuri e tamarindo foram as que apresentaram os menores teores de fenólicos totais. Com relação à atividade antioxidante in vitro, os melhores resultados foram encontrados para os extratos aquosos e hidroalcoólicos das polpas de acerola, caju e goiaba. A capacidade antioxidante destas polpas (EC50 em µg/mL variou de 24,42 a 413,36 e de 1,74 a 259,18 para os extratos aquosos e hidroalcoólicos, respectivamente. Utilizando o radical ABTS, a atividade antioxidante para essas mesmas polpas de frutas apresentou valores TEAC que

  18. Evolution Reveals A Glutathione-dependent Mechanism Of 3-hydroxypropionic Acid Detoxification

    DEFF Research Database (Denmark)

    Kildegaard, Kanchana Rueksomtawin; Hallström, Björn M.; Blicher, Thomas H.;

    Biologically produced 3-hydroxypropionic acid (3HP) is a potential source for sustainable acrylates and can also find direct use as monomer in the production of biodegradable polymers. For industrial-scale production, high titer, rate and yield are essential; thus there is a need for robust cell...... factories tolerant to high concentration of 3HP, preferably at low pH. Through adaptive laboratory evolution we selected S. cerevisiae strains with improved tolerance to 3HP at pH 3.5. Genome sequencing of three independent clones identified single-nucleotide changes in the SFA1 gene encoding S...... as a glutathione-dependent route for detoxification of 3-hydroxypropionic aldehyde (reuterin). The identified molecular response to 3HP and reuterin may well be a general mechanism for handling resistance to organic acids and aldehydes by living cells...

  19. Metabolite Profiling for Leaf Senescence in Barley Reveals Decreases in Amino Acids and Glycolysis Intermediates

    Directory of Open Access Journals (Sweden)

    Liliana Avila-Ospina

    2017-02-01

    Full Text Available Leaf senescence is a long developmental phase important for plant performance and nutrient management. Cell constituents are recycled in old leaves to provide nutrients that are redistributed to the sink organs. Up to now, metabolomic changes during leaf senescence have been mainly studied in Arabidopsis (Arabidopsis thaliana L.. The metabolite profiling conducted in barley (Hordeum vulgare L. during primary leaf senescence under two nitrate regimes and in flag leaf shows that amino acids, hexose, sucrose and glycolysis intermediates decrease during senescence, while minor carbohydrates accumulate. Tricarboxylic acid (TCA compounds changed with senescence only in primary leaves. The senescence-related metabolite changes in the flag leaf were globally similar to those observed in primary leaves. The effect of senescence on the metabolite changes of barley leaves was similar to that previously described in Arabidopsis except for sugars and glycolysis compounds. This suggests a different role of sugars in the control of leaf senescence in Arabidopsis and in barley.

  20. Structure of Human Acid Sphingomyelinase Reveals the Role of the Saposin Domain in Activating Substrate Hydrolysis.

    Science.gov (United States)

    Xiong, Zi-Jian; Huang, Jingjing; Poda, Gennady; Pomès, Régis; Privé, Gilbert G

    2016-07-31

    Acid sphingomyelinase (ASM) is a lysosomal phosphodiesterase that catalyzes the hydrolysis of sphingomyelin to produce ceramide and phosphocholine. While other lysosomal sphingolipid hydrolases require a saposin activator protein for full activity, the ASM polypeptide incorporates a built-in N-terminal saposin domain and does not require an external activator protein. Here, we report the crystal structure of human ASM and describe the organization of the three main regions of the enzyme: the N-terminal saposin domain, the proline-rich connector, and the catalytic domain. The saposin domain is tightly associated along an edge of the large, bowl-shaped catalytic domain and adopts an open form that exposes a hydrophobic concave surface approximately 30Å from the catalytic center. The calculated electrostatic potential of the enzyme is electropositive at the acidic pH of the lysosome, consistent with the strict requirement for the presence of acidic lipids in target membranes. Docking studies indicate that sphingomyelin binds with the ceramide-phosphate group positioned at the binuclear zinc center and molecular dynamic simulations indicate that the intrinsic flexibility of the saposin domain is important for monomer-dimer exchange and for membrane interactions. Overall, ASM uses a combination of electrostatic and hydrophobic interactions to cause local disruptions of target bilayers in order to bring the lipid headgroup to the catalytic center in a membrane-bound reaction.

  1. beta-Keratins in crocodiles reveal amino acid homology with avian keratins.

    Science.gov (United States)

    Ye, Changjiang; Wu, Xiaobing; Yan, Peng; Amato, George

    2010-03-01

    The DNA sequences encoding beta-keratin have been obtained from Marsh Mugger (Crocodylus palustris) and Orinoco Crocodiles (Crocodylus intermedius). Through the deduced amino acid sequence, these proteins are rich in glycine, proline and serine. The central region of the proteins are composed of two beta-folded regions and show a high degree of identity with beta-keratins of aves and squamates. This central part is thought to be the site of polymerization to build the framework of beta-keratin filaments. It is believed that the beta-keratins in reptiles and birds share a common ancestry. Near the C-terminal, these beta-keratins contain a peptide rich in glycine-X and glycine-X-X, and the distinctive feature of the region is some 12-amino acid repeats, which are similar to the 13-amino acid repeats in chick scale keratin but absent from avian feather keratin. From our phylogenetic analysis, the beta-keratins in crocodile have a closer relationship with avian keratins than the other keratins in reptiles.

  2. Identification of olivetolic acid cyclase from Cannabis sativa reveals a unique catalytic route to plant polyketides.

    Science.gov (United States)

    Gagne, Steve J; Stout, Jake M; Liu, Enwu; Boubakir, Zakia; Clark, Shawn M; Page, Jonathan E

    2012-07-31

    Δ(9)-Tetrahydrocannabinol (THC) and other cannabinoids are responsible for the psychoactive and medicinal properties of Cannabis sativa L. (marijuana). The first intermediate in the cannabinoid biosynthetic pathway is proposed to be olivetolic acid (OA), an alkylresorcinolic acid that forms the polyketide nucleus of the cannabinoids. OA has been postulated to be synthesized by a type III polyketide synthase (PKS) enzyme, but so far type III PKSs from cannabis have been shown to produce catalytic byproducts instead of OA. We analyzed the transcriptome of glandular trichomes from female cannabis flowers, which are the primary site of cannabinoid biosynthesis, and searched for polyketide cyclase-like enzymes that could assist in OA cyclization. Here, we show that a type III PKS (tetraketide synthase) from cannabis trichomes requires the presence of a polyketide cyclase enzyme, olivetolic acid cyclase (OAC), which catalyzes a C2-C7 intramolecular aldol condensation with carboxylate retention to form OA. OAC is a dimeric α+β barrel (DABB) protein that is structurally similar to polyketide cyclases from Streptomyces species. OAC transcript is present at high levels in glandular trichomes, an expression profile that parallels other cannabinoid pathway enzymes. Our identification of OAC both clarifies the cannabinoid pathway and demonstrates unexpected evolutionary parallels between polyketide biosynthesis in plants and bacteria. In addition, the widespread occurrence of DABB proteins in plants suggests that polyketide cyclases may play an overlooked role in generating plant chemical diversity.

  3. Proteomic Stable Isotope Probing Reveals Taxonomically Distinct Patterns in Amino Acid Assimilation by Coastal Marine Bacterioplankton.

    Science.gov (United States)

    Bryson, Samuel; Li, Zhou; Pett-Ridge, Jennifer; Hettich, Robert L; Mayali, Xavier; Pan, Chongle; Mueller, Ryan S

    2016-01-01

    Heterotrophic marine bacterioplankton are a critical component of the carbon cycle, processing nearly a quarter of annual primary production, yet defining how substrate utilization preferences and resource partitioning structure microbial communities remains a challenge. In this study, proteomic stable isotope probing (proteomic SIP) was used to characterize population-specific assimilation of dissolved free amino acids (DFAAs), a major source of dissolved organic carbon for bacterial secondary production in aquatic environments. Microcosms of seawater collected from Newport, Oregon, and Monterey Bay, California, were incubated with 1 µM (13)C-labeled amino acids for 15 and 32 h. The taxonomic compositions of microcosm metaproteomes were highly similar to those of the sampled natural communities, with Rhodobacteriales, SAR11, and Flavobacteriales representing the dominant taxa. Analysis of (13)C incorporation into protein biomass allowed for quantification of the isotopic enrichment of identified proteins and subsequent determination of differential amino acid assimilation patterns between specific bacterioplankton populations. Proteins associated with Rhodobacterales tended to have a significantly high frequency of (13)C-enriched peptides, opposite the trend for Flavobacteriales and SAR11 proteins. Rhodobacterales proteins associated with amino acid transport and metabolism had an increased frequency of (13)C-enriched spectra at time point 2. Alteromonadales proteins also had a significantly high frequency of (13)C-enriched peptides, particularly within ribosomal proteins, demonstrating their rapid growth during incubations. Overall, proteomic SIP facilitated quantitative comparisons of DFAA assimilation by specific taxa, both between sympatric populations and between protein functional groups within discrete populations, allowing an unprecedented examination of population level metabolic responses to resource acquisition in complex microbial communities

  4. Insight toward epithelial Na+ channel mechanism revealed by the acid-sensing ion channel 1 structure.

    Science.gov (United States)

    Stockand, James D; Staruschenko, Alexander; Pochynyuk, Oleh; Booth, Rachell E; Silverthorn, Dee U

    2008-09-01

    The epithelial Na(+) channel/degenerin (ENaC/DEG) protein family includes a diverse group of ion channels, including nonvoltage-gated Na(+) channels of epithelia and neurons, and the acid-sensing ion channel 1 (ASIC1). In mammalian epithelia, ENaC helps regulate Na(+) and associated water transport, making it a critical determinant of systemic blood pressure and pulmonary mucosal fluidity. In the nervous system, ENaC/DEG proteins are related to sensory transduction. While the importance and physiological function of these ion channels are established, less is known about their structure. One hallmark of the ENaC/DEG channel family is that each channel subunit has only two transmembrane domains connected by an exceedingly large extracellular loop. This subunit structure was recently confirmed when Jasti and colleagues determined the crystal structure of chicken ASIC1, a neuronal acid-sensing ENaC/DEG channel. By mapping ENaC to the structural coordinates of cASIC1, as we do here, we hope to provide insight toward ENaC structure. ENaC, like ASIC1, appears to be a trimeric channel containing 1alpha, 1beta, and 1gamma subunit. Heterotrimeric ENaC and monomeric ENaC subunits within the trimer possibly contain many of the major secondary, tertiary, and quaternary features identified in cASIC1 with a few subtle but critical differences. These differences are expected to have profound effects on channel behavior. In particular, they may contribute to ENaC insensitivity to acid and to its constitutive activity in the absence of time- and ligand-dependent inactivation. Experiments resulting from this comparison of cASIC1 and ENaC may help clarify unresolved issues related to ENaC architecture, and may help identify secondary structures and residues critical to ENaC function.

  5. Contrasting species-environment relationships in communities of testate amoebae, bryophytes and vascular plants along the fen-bog gradient.

    Science.gov (United States)

    Lamentowicz, Mariusz; Lamentowicz, Lukasz; van der Knaap, Willem O; Gabka, Maciej; Mitchell, Edward A D

    2010-04-01

    We studied the vegetation, testate amoebae and abiotic variables (depth of the water table, pH, electrical conductivity, Ca and Mg concentrations of water extracted from mosses) along the bog to extremely rich fen gradient in sub-alpine peatlands of the Upper Engadine (Swiss Alps). Testate amoeba diversity was correlated to that of mosses but not of vascular plants. Diversity peaked in rich fen for testate amoebae and in extremely rich fen for mosses, while for testate amoebae and mosses it was lowest in bog but for vascular plants in extremely rich fen. Multiple factor and redundancy analyses (RDA) revealed a stronger correlation of testate amoebae than of vegetation to water table and hydrochemical variables and relatively strong correlation between testate amoeba and moss community data. In RDA, hydrochemical variables explained a higher proportion of the testate amoeba and moss data than water table depth. Abiotic variables explained a higher percentage of the species data for testate amoebae (30.3% or 19.5% for binary data) than for mosses (13.4%) and vascular plants (10%). These results show that (1) vascular plant, moss and testate amoeba communities respond differently to ecological gradients in peatlands and (2) testate amoebae are more strongly related than vascular plants to the abiotic factors at the mire surface. These differences are related to vertical trophic gradients and associated niche differentiation.

  6. Revealing the Molecular Structural Transformation of Hardwood and Softwood in Dilute Acid Flowthrough Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Libing; Pu, Yunqiao; Cort, John R.; Ragauskas, Arthur J.; Yang, Bin

    2016-12-05

    To better understand the intrinsic recalcitrance of lignocellulosic biomass, the main hurdle to its efficient deconstruction, the effects of dilute acid flowthrough pretreatment on the dissolution chemistry of hemicellulose, cellulose, and lignin for both hardwood (e.g. poplar wood) and softwood (e.g. lodgepole pine wood) were investigated at temperatures of 200 °C to 270 °C and a flow rate of 25 mL/minute with 0.05% (w/w) H2SO4. Results suggested that the softwood cellulose was more readily to be degraded into monomeric sugars than that of hardwood under same pretreatment conditions. However, while the hardwood lignin was completely removed into hydrolysate, ~30% of the softwood lignin remained as solid residues under identical conditions, which was plausibly caused by vigorous C5-active recondensation reactions (C-C5). Unique molecular structural features that pronounced the specific recalcitrance of hardwood and softwood to dilute acid pretreatment were identified for the first time in this study, providing important insights to establish the effective biomass pretreatment.

  7. RNA arbitrarily primed PCR and fourier transform infrared spectroscopy reveal plasticity in the acid tolerance response of Streptococcus macedonicus.

    Science.gov (United States)

    Papadimitriou, Konstantinos; Boutou, Effrossyni; Zoumpopoulou, Georgia; Tarantilis, Petros A; Polissiou, Moschos; Vorgias, Constantinos E; Tsakalidou, Effie

    2008-10-01

    We have previously reported that an acid tolerance response (ATR) can be induced in Streptococcus macedonicus cells at mid-log phase after autoacidification, transient exposure to acidic pH, or acid habituation, as well as at stationary phase. Here, we compared the transcriptional profiles of these epigenetic phenotypes, by RNA arbitrarily primed PCR (RAP-PCR), and their whole-cell chemical compositions, by Fourier transform infrared spectroscopy (FT-IR). RAP-PCR fingerprints revealed significant differences among the phenotypes, indicating that gene expression during the ATR is influenced not only by the growth phase but also by the treatments employed to induce the response. The genes coding for the mannose-specific IID component, the 1,2-diacylglycerol 3-glucosyltransferase, the 3-oxoacyl-acyl carrier protein, the large subunit of carbamoyl-phosphate synthase, and a hypothetical protein were found to be induced at least under some of the acid-adapting conditions. Furthermore, principal component analysis of the second-derivative-transformed FT-IR spectra segregated S. macedonicus phenotypes individually in all spectral regions that are characteristic for major cellular constituents like the polysaccharides of the cell wall, fatty acids of the cell membrane, proteins, and other compounds that absorb in these regions. These findings provide evidence for major changes in cellular composition due to acid adaptation that were clearly different to some extent among the phenotypes. Overall, our data demonstrate the plasticity in the ATR of S. macedonicus, which reflects the inherent ability of the bacterium to adjust the response to the distinctiveness of the imposed stress condition, probably to maximize its adaptability.

  8. Down-regulation of the Caffeic acid O-methyltransferase Gene in Switchgrass Reveals a Novel Monolignol Analog

    Energy Technology Data Exchange (ETDEWEB)

    Tschaplinski, Timothy J [ORNL; Standaert, Robert F [ORNL; Engle, Nancy L [ORNL; Martin, Madhavi Z [ORNL; Sangha, Amandeep K [ORNL; Parks, Jerry M [ORNL; Smith, Jeremy C [ORNL; Samuel, Reichel [ORNL; Pu, Yunqiao [ORNL; Ragauskas, A J [Georgia Institute of Technology; Hamilton, Choo Yieng [ORNL; Fu, Chunxiang [Noble Foundation; Wang, Zeng-Yu [Noble Foundation; Davison, Brian H [ORNL; Dixon, Richard A [Noble Foundation; Mielenz, Jonathan R [ORNL

    2012-01-01

    Down-regulation of the caffeic acid 3-O-methyltransferase (COMT) gene in the lignin biosynthetic pathway of switchgrass (Panicum virgatum) resulted in cell walls of transgenic plants releasing more constituent sugars after pretreatment by dilute acid and treatment with glycosyl hydrolases from an added enzyme preparation and from Clostridium thermocellum. Fermentation of both wild-type and transgenic switchgrass after milder hot water pretreatment with no water washing showed that only the transgenic switchgrass inhibited C. thermocellum. Gas chromatography-mass spectrometry-based metabolomics were undertaken on cell wall aqueous extracts to determine the nature of the microbial inhibitors, confirming the increased concentration of a number of phenolic acids and aldehydes that are known inhibitors of fermentation. Metabolomic analyses of the transgenic biomass additionally revealed the presence of a novel monolignol-like metabolite, identified as trans-3, 4-dimethoxy-5-hydroxycinnamyl alcohol (iso-sinapyl alcohol) in both non-pretreated, as well as hot water pretreated samples. Although there was no indication that iso-sinapyl alcohol was integrated into the cell wall, diversion of substrates from sinapyl alcohol to free iso-sinapyl alcohol, its glucoside, and associated upstream lignin pathway changes, including increased phenolic aldehydes and acids, are associated with more facile cell wall deconstruction, and to the observed inhibitory effect on microbial growth.

  9. In situ proteo-metabolomics reveals metabolite secretion by the acid mine drainage bio-indicator, Euglena mutabilis.

    Science.gov (United States)

    Halter, David; Goulhen-Chollet, Florence; Gallien, Sébastien; Casiot, Corinne; Hamelin, Jérôme; Gilard, Françoise; Heintz, Dimitri; Schaeffer, Christine; Carapito, Christine; Van Dorsselaer, Alain; Tcherkez, Guillaume; Arsène-Ploetze, Florence; Bertin, Philippe N

    2012-07-01

    Euglena mutabilis is a photosynthetic protist found in acidic aquatic environments such as peat bogs, volcanic lakes and acid mine drainages (AMDs). Through its photosynthetic metabolism, this protist is supposed to have an important role in primary production in such oligotrophic ecosystems. Nevertheless, the exact contribution of E. mutabilis in organic matter synthesis remains unclear and no evidence of metabolite secretion by this protist has been established so far. Here we combined in situ proteo-metabolomic approaches to determine the nature of the metabolites accumulated by this protist or potentially secreted into an AMD. Our results revealed that the secreted metabolites are represented by a large number of amino acids, polyamine compounds, urea and some sugars but no fatty acids, suggesting a selective organic matter contribution in this ecosystem. Such a production may have a crucial impact on the bacterial community present on the study site, as it has been suggested previously that prokaryotes transport and recycle in situ most of the metabolites secreted by E. mutabilis. Consequently, this protist may have an indirect but important role in AMD ecosystems but also in other ecological niches often described as nitrogen-limited.

  10. A transcriptomic study reveals differentially expressed genes and pathways respond to simulated acid rain in Arabidopsis thaliana.

    Science.gov (United States)

    Liu, Ting-Wu; Niu, Li; Fu, Bin; Chen, Juan; Wu, Fei-Hua; Chen, Juan; Wang, Wen-Hua; Hu, Wen-Jun; He, Jun-Xian; Zheng, Hai-Lei

    2013-01-01

    Acid rain, as a worldwide environmental issue, can cause serious damage to plants. In this study, we provided the first case study on the systematic responses of arabidopsis (Arabidopsis thaliana (L.) Heynh.) to simulated acid rain (SiAR) by transcriptome approach. Transcriptomic analysis revealed that the expression of a set of genes related to primary metabolisms, including nitrogen, sulfur, amino acid, photosynthesis, and reactive oxygen species metabolism, were altered under SiAR. In addition, transport and signal transduction related pathways, especially calcium-related signaling pathways, were found to play important roles in the response of arabidopsis to SiAR stress. Further, we compared our data set with previously published data sets on arabidopsis transcriptome subjected to various stresses, including wound, salt, light, heavy metal, karrikin, temperature, osmosis, etc. The results showed that many genes were overlapped in several stresses, suggesting that plant response to SiAR is a complex process, which may require the participation of multiple defense-signaling pathways. The results of this study will help us gain further insights into the response mechanisms of plants to acid rain stress.

  11. Negative Ion Photoelectron Spectroscopy Reveals Thermodynamic Advantage of Organic Acids in Facilitating Formation of Bisulfate Ion Clusters: Atmospheric Implications

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Gao-Lei; Lin, Wei; Deng, Shihu; Zhang, Jian; Zheng, Weijun; Paesani, Francesco; Wang, Xue B.

    2013-03-07

    Recent lab and field measurements have indicated critical roles of organic acids in enhancing new atmospheric aerosol formation. Such findings have stimulated theoretical studies with the aim of understanding interaction of organic acids with common aerosol nucleation precursors like bisulfate (HSO4-). In this Letter, we report a combined negative ion photoelectron spectroscopic and theoretical investigation of molecular clusters formed by HSO4- with succinic acid (SUA, HO2C(CH2)2CO2H), HSO4-(SUA)n (n = 0-2), along with HSO4-(H2O)n and HSO4-(H2SO4)n. It is found that one SUA molecule can stabilize HSO4- by ca. 39 kcal/mol, triple the corresponding value that one water molecule is capable of (ca. 13 kcal/mol). Molecular dynamics simulations and quantum chemical calculations reveal the most plausible structures of these clusters and attribute the stability of these clusters due to formation of strong hydrogen bonds. This work provides direct experimental evidence showing significant thermodynamic advantage by involving organic acid molecules to promote formation and growth in bisulfate clusters and aerosols.

  12. Structure of Vibrio cholerae ToxT reveals a mechanism for fatty acid regulation of virulence genes

    Energy Technology Data Exchange (ETDEWEB)

    Lowden, Michael J.; Skorupski, Karen; Pellegrini, Maria; Chiorazzo, Michael G.; Taylor, Ronald K.; Kull, F. Jon (Dartmouth)

    2010-03-04

    Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae. In order for V. cholerae to cause disease, it must produce two virulence factors, the toxin-coregulated pilus (TCP) and cholera toxin (CT), whose expression is controlled by a transcriptional cascade culminating with the expression of the AraC-family regulator, ToxT. We have solved the 1.9 {angstrom} resolution crystal structure of ToxT, which reveals folds in the N- and C-terminal domains that share a number of features in common with AraC, MarA, and Rob as well as the unexpected presence of a buried 16-carbon fatty acid, cis-palmitoleate. The finding that cis-palmitoleic acid reduces TCP and CT expression in V. cholerae and prevents ToxT from binding to DNA in vitro provides a direct link between the host environment of V. cholerae and regulation of virulence gene expression.

  13. Stable isotope tracer reveals that viviparous snakes transport amino acids to offspring during gestation.

    Science.gov (United States)

    Van Dyke, James U; Beaupre, Steven J

    2012-03-01

    Viviparity and placentation have evolved from oviparity over 100 times in squamate reptiles (lizards and snakes). The independent origins of placentation have resulted in a variety of placental morphologies in different taxa, ranging from simple apposition of fetal and maternal tissues to endotheliochorial implantation that is homoplasious with mammalian placentation. Because the eggs of oviparous squamates transport gases and water from the environment and calcium from the eggshell, the placentae of viviparous squamates are thought to have initially evolved to accomplish these functions from within the maternal oviduct. Species with complex placentae have also been shown to rely substantially, or even primarily, on placental transport of organic nutrients for embryonic nutrition. However, it is unclear whether species with only simple placentae are also capable of transporting organic nutrients to offspring. Among viviparous squamates, all of the snakes that have been studied thus far have been shown to have simple placentae. However, most studies of snake placentation are limited to a single lineage, the North American Natricinae. We tested the abilities of four species of viviparous snakes - Agkistrodon contortrix (Viperidae), Boa constrictor (Boidae), Nerodia sipedon (Colubridae: Natricinae) and Thamnophis sirtalis (Colubridae: Natricinae) - to transport diet-derived amino acids to offspring during gestation. We fed [(15)N]leucine to pregnant snakes, and compared offspring (15)N content with that of unlabeled controls. Labeled females allocated significantly more (15)N to offspring than did controls, but (15)N allocation did not differ among species. Our results indicate that viviparous snakes are capable of transporting diet-derived amino acids to their offspring during gestation, possibly via placentation.

  14. Proteomic analysis revealed alterations of the Plasmodium falciparum metabolism following salicylhydroxamic acid exposure

    Directory of Open Access Journals (Sweden)

    Torrentino-Madamet M

    2011-09-01

    Full Text Available Marylin Torrentino-Madamet1, Lionel Almeras2, Christelle Travaillé1, Véronique Sinou1, Matthieu Pophillat3, Maya Belghazi4, Patrick Fourquet3, Yves Jammes5, Daniel Parzy11UMR-MD3, Université de la Méditerranée, Antenne IRBA de Marseille (IMTSSA, Le Pharo, 2Unité de Recherche en Biologie et Epidémiologie Parasitaires, Antenne IRBA de Marseille (IMTSSA, Le Pharo, 3Centre d'Immunologie de Marseille Luminy, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Université de la Méditerranée, 4Centre d'Analyse Protéomique de Marseille, Institut Fédératif de Recherche Jean Roche, Faculté de Médecine Nord, 5UMR-MD2, Physiologie et Physiopathologie en Conditions d'Oxygénations Extrêmes, Institut Fédératif de Recherche Jean Roche, Faculté de Médecine Nord, Marseille, FranceObjectives: Although human respiratory metabolism is characterized by the mitochondrial electron transport chain, some organisms present a “branched respiratory chain.” This branched pathway includes both a classical and an alternative respiratory chain. The latter involves an alternative oxidase. Though the Plasmodium falciparum alternative oxidase is not yet identified, a specific inhibitor of this enzyme, salicylhydroxamic acid (SHAM, showed a drug effect on P. falciparum respiratory function using oxygen consumption measurements. The present study aimed to highlight the metabolic pathways that are affected in P. falciparum following SHAM exposure.Design: A proteomic approach was used to analyze the P. falciparum proteome and determine the metabolic pathways altered following SHAM treatment. To evaluate the SHAM effect on parasite growth, the phenotypic alterations of P. falciparum after SHAM or/and hyperoxia exposure were observed.Results: After SHAM exposure, 26 proteins were significantly deregulated using a fluorescent two dimensional-differential gel electrophoresis. Among these deregulated proteins

  15. Plasma lipidomics reveal profound perturbation of glycerophospholipids, fatty acids, and sphingolipids in diet-induced hyperlipidemia.

    Science.gov (United States)

    Miao, Hua; Chen, Hua; Pei, Songwen; Bai, Xu; Vaziri, Nosratola D; Zhao, Ying-Yong

    2015-02-25

    Hyperlipidemia is a major risk factor for coronary heart disease and has emerged as an important public health problem. Lipidomics is a powerful technology for assessment of global lipid metabolites in a biological system and for biomarker discovery. In the present study, hyperlipidemia was induced by feeding rats a high fat diet. A sensitive ultra-performance liquid chromatography coupled with quadrupole time-of-flight synapt high-definition mass spectrometry method was used for the analysis of plasma lipids. Orthogonal partial least squares-discriminant analysis, correlation analysis and heatmap analysis were performed to investigate the metabolic changes in rats with diet-induced hyperlipidemia. Potential biomarkers were detected using S-plot and were identified by accurate mass data, isotopic pattern and MS(E) fragments information. Significantly increased total cholesterol, triglycerides and low-density lipoprotein cholesterol as well as decreased high-density lipoprotein cholesterol were observed in diet-induced hyperlipidemic rats. Combined with standard serum biochemical results, significant differences in plasma lipid compounds including eleven glycerophospholipids, six fatty acids, two sphingolipids, one eicosanoid, one sterol lipid and one glycerolipid were observed, highlighting the perturbation of lipid metabolism in diet-induced hyperlipidemia. These findings provide further insights into the lipid profile across a wide range of biochemical pathways in diet-induced hyperlipidemia.

  16. Competing mechanisms for perfluoroalkyl acid accumulation in plants revealed using an Arabidopsis model system.

    Science.gov (United States)

    Müller, Claudia E; LeFevre, Gregory H; Timofte, Anca E; Hussain, Fatima A; Sattely, Elizabeth S; Luthy, Richard G

    2016-05-01

    Perfluoroalkyl acids (PFAAs) bioaccumulate in plants, presenting a human exposure route if present in irrigation water. Curiously, accumulation of PFAAs in plant tissues is greatest for both the short-chain and long-chain PFAAs, generating a U-shaped relationship with chain length. In the present study, the authors decouple competing mechanisms of PFAA accumulation using a hydroponic model plant system (Arabidopsis thaliana) exposed to a suite of 10 PFAAs to determine uptake, depuration, and translocation kinetics. Rapid saturation of root concentrations occurred for all PFAAs except perfluorobutanoate, the least-sorptive (shortest-chain) PFAA. Shoot concentrations increased continuously, indicating that PFAAs are efficiently transported and accumulate in shoots. Tissue concentrations of PFAAs during depuration rapidly declined in roots but remained constant in shoots, demonstrating irreversibility of the translocation process. Root and shoot concentration factors followed the U-shaped trend with perfluoroalkyl chain length; however, when normalized to dead-tissue sorption, this relationship linearized. The authors therefore introduce a novel term, the "sorption normalized concentration factor," to describe PFAA accumulation in plants; because of their hydrophobicity, sorption is the determining factor for long-chain PFAAs, whereas the shortest-chain PFAAs are most effectively transported in the plant. The present study provides a mechanistic explanation for previously unexplained PFAA accumulation trends in plants and suggests that shorter-chained PFAAs may bioaccumulate more readily in edible portions.

  17. Transcriptomic analysis reveals the metabolic mechanism of L-ascorbic acid in Ziziphus jujuba Mill.

    Directory of Open Access Journals (Sweden)

    Chunmei eZhang

    2016-02-01

    Full Text Available Chinese jujube (Ziziphus jujuba Mill. is the most economically important member of the Rhamnaceae family and contains a high concentration of ascorbic acid (AsA. To explore the metabolic mechanism of AsA accumulation, we investigated the abundance of AsA in the fruit development stages, the leaf and flower of Z. jujuba cv Junzao, and the mature fruit of one type of wild jujube (Z. jujuba var. spinosa Hu, Yanchuan sour jujube. And the expression patterns of genes involved in AsA biosynthesis, degradation and recycling were analyzed. The result showed that AsA biosynthesis during early fruit development (the enlargement stage is the main reason for jujube high accumulation. The L-galactose pathway plays a predominant role in the biosynthesis of AsA during jujube fruit development, and the genes GMP1, GME1, GGP, and GaLDH involved in the determination of AsA concentration during fruit development and in different genotypes; the myo-inositol pathway along with the genes GME2 and GMP2 in the L-galactose pathway play a compensatory role in maintaining AsA accumulation during the ripening stage. These findings enhance our understanding of the molecular mechanism in regulating AsA accumulation for jujube.

  18. Multiple actions of lysophosphatidic acid on fibroblasts revealed by transcriptional profiling

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    Moolenaar Wouter H

    2008-08-01

    Full Text Available Abstract Background Lysophosphatidic acid (LPA is a lipid mediator that acts through specific G protein-coupled receptors to stimulate the proliferation, migration and survival of many cell types. LPA signaling has been implicated in development, wound healing and cancer. While LPA signaling pathways have been studied extensively, it remains unknown how LPA affects global gene expression in its target cells. Results We have examined the temporal program of global gene expression in quiescent mouse embryonic fibroblasts stimulated with LPA using 32 k oligonucleotide microarrays. In addition to genes involved in growth stimulation and cytoskeletal reorganization, LPA induced many genes that encode secreted factors, including chemokines, growth factors, cytokines, pro-angiogenic and pro-fibrotic factors, components of the plasminogen activator system and metalloproteases. Strikingly, epidermal growth factor induced a broadly overlapping expression pattern, but some 7% of the genes (105 out of 1508 transcripts showed differential regulation by LPA. The subset of LPA-specific genes was enriched for those associated with cytoskeletal remodeling, in keeping with LPA's ability to regulate cell shape and motility. Conclusion This study highlights the importance of LPA in programming fibroblasts not only to proliferate and migrate but also to produce many paracrine mediators of tissue remodeling, angiogenesis, inflammation and tumor progression. Furthermore, our results show that G protein-coupled receptors and receptor tyrosine kinases can signal independently to regulate broadly overlapping sets of genes in the same cell type.

  19. Comparative Transcriptome Analysis Reveals the Influence of Abscisic Acid on the Metabolism of Pigments, Ascorbic Acid and Folic Acid during Strawberry Fruit Ripening.

    Science.gov (United States)

    Li, Dongdong; Li, Li; Luo, Zisheng; Mou, Wangshu; Mao, Linchun; Ying, Tiejin

    2015-01-01

    A comprehensive investigation of abscisic acid (ABA) biosynthesis and its influence on other important phytochemicals is critical for understanding the versatile roles that ABA plays during strawberry fruit ripening. Using RNA-seq technology, we sampled strawberry fruit in response to ABA or nordihydroguaiaretic acid (NDGA; an ABA biosynthesis blocker) treatment during ripening and assessed the expression changes of genes involved in the metabolism of pigments, ascorbic acid (AsA) and folic acid in the receptacles. The transcriptome analysis identified a lot of genes differentially expressed in response to ABA or NDGA treatment. In particular, genes in the anthocyanin biosynthesis pathway were actively regulated by ABA, with the exception of the gene encoding cinnamate 4-hydroxylase. Chlorophyll degradation was accelerated by ABA mainly owing to the higher expression of gene encoding pheide a oxygenase. The decrease of β-carotene content was accelerated by ABA treatment and delayed by NDGA. A high negative correlation rate was found between ABA and β-carotene content, indicating the importance of the requirement for ABA synthesis during fruit ripening. In addition, evaluation on the folate biosynthetic pathway indicate that ABA might have minor function in this nutrient's biosynthesis process, however, it might be involved in its homeostasis. Surprisingly, though AsA content accumulated during fruit ripening, expressions of genes involved in its biosynthesis in the receptacles were significantly lower in ABA-treated fruits. This transcriptome analysis expands our understanding of ABA's role in phytochemical metabolism during strawberry fruit ripening and the regulatory mechanisms of ABA on these pathways were discussed. Our study provides a wealth of genetic information in the metabolism pathways and may be helpful for molecular manipulation in the future.

  20. Comparative Transcriptome Analysis Reveals the Influence of Abscisic Acid on the Metabolism of Pigments, Ascorbic Acid and Folic Acid during Strawberry Fruit Ripening.

    Directory of Open Access Journals (Sweden)

    Dongdong Li

    Full Text Available A comprehensive investigation of abscisic acid (ABA biosynthesis and its influence on other important phytochemicals is critical for understanding the versatile roles that ABA plays during strawberry fruit ripening. Using RNA-seq technology, we sampled strawberry fruit in response to ABA or nordihydroguaiaretic acid (NDGA; an ABA biosynthesis blocker treatment during ripening and assessed the expression changes of genes involved in the metabolism of pigments, ascorbic acid (AsA and folic acid in the receptacles. The transcriptome analysis identified a lot of genes differentially expressed in response to ABA or NDGA treatment. In particular, genes in the anthocyanin biosynthesis pathway were actively regulated by ABA, with the exception of the gene encoding cinnamate 4-hydroxylase. Chlorophyll degradation was accelerated by ABA mainly owing to the higher expression of gene encoding pheide a oxygenase. The decrease of β-carotene content was accelerated by ABA treatment and delayed by NDGA. A high negative correlation rate was found between ABA and β-carotene content, indicating the importance of the requirement for ABA synthesis during fruit ripening. In addition, evaluation on the folate biosynthetic pathway indicate that ABA might have minor function in this nutrient's biosynthesis process, however, it might be involved in its homeostasis. Surprisingly, though AsA content accumulated during fruit ripening, expressions of genes involved in its biosynthesis in the receptacles were significantly lower in ABA-treated fruits. This transcriptome analysis expands our understanding of ABA's role in phytochemical metabolism during strawberry fruit ripening and the regulatory mechanisms of ABA on these pathways were discussed. Our study provides a wealth of genetic information in the metabolism pathways and may be helpful for molecular manipulation in the future.

  1. Characterization of volatile compounds in Fen-Daqu - a traditional Chinese liquor fermentation starter

    NARCIS (Netherlands)

    Van-Diep, L.; Zheng, X.; Chen, J.Y.; Han, B.Z.

    2012-01-01

    Fen-Daqu is a saccharifying agent and fermentation starter for the production of Chinese liquor Fen (alcoholic spirit) and Fen traditional vinegar. The volatile compounds produced at seven incubation steps were analysed by HS-SPME-GC-MS. A total of 83 major volatile compounds were identified, includ

  2. Species trait shifts in vegetation and soil seed bank during fen degradation

    NARCIS (Netherlands)

    Klimkowska, A.; Bekker, R.M.; Diggelen, R.; Kotowski, W.

    2010-01-01

    Fens in Central Europe are characterised by waterlogged organic substrate and low productivity. Human-induced changes due to drainage and mowing lead to changes in plant species composition from natural fen communities to fen meadows and later to over-drained, degraded meadows. Moderate drainage lea

  3. Vagues / Fenêtres for String Trio and Electronic Sounds

    OpenAIRE

    Ficarra, Evelyn Jacqueline

    2010-01-01

    AbstractVagues / Fenêtres for String Trio and Electronic SoundsbyEvelyn Jacqueline FicarraDoctor of Philosophy in MusicUniversity of California, BerkeleyProfessor Edmund Campion, ChairThis research begins with close listening: `close' being an attitude of intense focus, directed both outwards to sounds in the real world and inwards to the imagination. `Close' also being an apt description of technologically assisted listening, through `close miking' techniques in the recording process; `close...

  4. DNA methylation profiling at single-base resolution reveals gestational folic acid supplementation influences the epigenome of mouse offspring cerebellum

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    Subit eBarua

    2016-05-01

    Full Text Available It is becoming increasingly more evident that lifestyle, environmental factors, and maternal nutrition during gestation can influence the epigenome of the developing fetus and thus modulate the physiological outcome. Variations in the intake of maternal nutrients affecting one-carbon metabolism may influence brain development and exert long-term effects on the health of the progeny. In this study, we investigated whether supplementation with high maternal folic acid during gestation alters DNA methylation and gene expression in the cerebellum of mouse offspring. We used reduced representation bisulfite sequencing to analyze the DNA methylation profile at the single-base resolution level. The genome-wide DNA methylation analysis revealed that supplementation with higher maternal folic acid resulted in distinct methylation patterns (P < 0.05 of CpG and non-CpG sites in the cerebellum of offspring. Such variations of methylation and gene expression in the cerebellum of offspring were highly sex-specific, including several genes of the neuronal pathways. These findings demonstrate that alterations in the level of maternal folic acid during gestation can influence methylation and gene expression in the cerebellum of offspring. Such changes in the offspring epigenome may alter neurodevelopment and influence the functional outcome of neurologic and psychiatric diseases.

  5. Fenómeno de Raynaud. Revisión

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    Jairo Alonso Rodríguez-Criollo

    2014-07-01

    Full Text Available El fenómeno de Raynaud es una respuesta vascular exagerada al frío o al estrés que se manifiesta por cambios de coloración de la piel en diversas localizaciones; característicamente, presenta tres fases distintas que comprenden palidez, cianosis y rubor. Dependiendo de la ausencia o la presencia de enfermedad de base, el fenómeno se denomina como primario o secundario, siendo este último subtipo una manifestación importante de enfermedades graves, principalmente autoinmunes. El fenómeno de Raynaud primario tiene buen pronóstico y la posibilidad de manejo por médico primario; por el contrario, el secundario implica la necesidad de evaluación y manejo especializado. Es de importancia para el médico general conocer su clasificación, las bases del manejo para control de los signos y síntomas, además de identificar cuándo un paciente requiere valoración y manejo especializado de acuerdo con otras enfermedades de base que puedan coexistir.

  6. El fenómeno de bullying en Colombia

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    Ángela Paola Contreras Álvarez

    2013-01-01

    Full Text Available El presente artículo describe el nefasto fenómeno de violencia y hostigamiento en ambientes escolares denominado bullying o matoneo escolar, el cual, aunque ha sido analizado desde finales de los años setenta en los países escandinavos, tuvo auge en Colombia en el año 2000, adquiriendo fuerza y permanencia con el uso de redes sociales, evidenciando la falta de políticas nacionales educativas para la atención e intervención del problema, al igual que el olvido de educación en derechos humanos y resolución pacífica de conflictos en los colegios. Esta problemática se desarrolla a través del significado del bullying, la descripción de sus antecedentes, descripción general del fenómeno, relación de los deberes del Estado frente al tema, la concepción del fenómeno desde la perspectiva de la Corte Constitucional, concluyendo en algunas sugerencias para abordar la problemática escolar.

  7. Transcriptome Profiling of Tomato Fruit Development Reveals Transcription Factors Associated with Ascorbic Acid, Carotenoid and Flavonoid Biosynthesis.

    Science.gov (United States)

    Ye, Jie; Hu, Tixu; Yang, Congmei; Li, Hanxia; Yang, Mingze; Ijaz, Raina; Ye, Zhibiao; Zhang, Yuyang

    2015-01-01

    Tomato (Solanum lycopersicum) serves as a research model for fruit development; however, while it is an important dietary source of antioxidant nutrients, the transcriptional regulation of genes that determine nutrient levels remains poorly understood. Here, the transcriptomes of fruit at seven developmental stages (7, 14, 21, 28, 35, 42 and 49 days after flowering) from two tomato cultivars (Ailsa Craig and HG6-61) were evaluated using the Illumina sequencing platform. A total of 26,397 genes, which were expressed in at least one developmental stage, were detected in the two cultivars, and the expression patterns of those genes could be divided into 20 groups using a K-mean cluster analysis. Gene Ontology term enrichment analysis indicated that genes involved in RNA regulation, secondary metabolism, hormone metabolism and cell wall metabolism were the most highly differentially expressed genes during fruit development and ripening. A co-expression analysis revealed several transcription factors whose expression patterns correlated with those of genes associated with ascorbic acid, carotenoid and flavonoid biosynthesis. This transcriptional correlation was confirmed by agroinfiltration mediated transient expression, which showed that most of the enzymatic genes in the ascorbic acid biosynthesis were regulated by the overexpression of each of the three transcription factors that were tested. The metabolic dynamics of ascorbic acid, carotenoid and flavonoid were investigated during fruit development and ripening, and some selected transcription factors showed transcriptional correlation with the accumulation of ascorbic acid, carotenoid and flavonoid. This transcriptome study provides insight into the regulatory mechanism of fruit development and presents candidate transcription factors involved in secondary metabolism.

  8. Transcriptome Profiling of Tomato Fruit Development Reveals Transcription Factors Associated with Ascorbic Acid, Carotenoid and Flavonoid Biosynthesis.

    Directory of Open Access Journals (Sweden)

    Jie Ye

    Full Text Available Tomato (Solanum lycopersicum serves as a research model for fruit development; however, while it is an important dietary source of antioxidant nutrients, the transcriptional regulation of genes that determine nutrient levels remains poorly understood. Here, the transcriptomes of fruit at seven developmental stages (7, 14, 21, 28, 35, 42 and 49 days after flowering from two tomato cultivars (Ailsa Craig and HG6-61 were evaluated using the Illumina sequencing platform. A total of 26,397 genes, which were expressed in at least one developmental stage, were detected in the two cultivars, and the expression patterns of those genes could be divided into 20 groups using a K-mean cluster analysis. Gene Ontology term enrichment analysis indicated that genes involved in RNA regulation, secondary metabolism, hormone metabolism and cell wall metabolism were the most highly differentially expressed genes during fruit development and ripening. A co-expression analysis revealed several transcription factors whose expression patterns correlated with those of genes associated with ascorbic acid, carotenoid and flavonoid biosynthesis. This transcriptional correlation was confirmed by agroinfiltration mediated transient expression, which showed that most of the enzymatic genes in the ascorbic acid biosynthesis were regulated by the overexpression of each of the three transcription factors that were tested. The metabolic dynamics of ascorbic acid, carotenoid and flavonoid were investigated during fruit development and ripening, and some selected transcription factors showed transcriptional correlation with the accumulation of ascorbic acid, carotenoid and flavonoid. This transcriptome study provides insight into the regulatory mechanism of fruit development and presents candidate transcription factors involved in secondary metabolism.

  9. Lipidomics analysis reveals efficient storage of hepatic triacylglycerides enriched in unsaturated fatty acids after one bout of exercise in mice.

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    Chunxiu Hu

    Full Text Available BACKGROUND: Endurance exercise induces lipolysis, increases circulating concentrations of free fatty acids (FFA and the uptake and oxidation of fatty acids in the working muscle. Less is known about the regulation of lipid metabolism in the liver during and post-exercise. METHODOLOGY/PRINCIPAL FINDINGS: We performed an ultra fast liquid chromatography-mass spectrometry (UFLC-MS based lipidomics analysis of liver tissue samples obtained from C57Bl/6J mice immediately after a 60 min treadmill run of moderate intensity, and after 3 h of recovery. The PLS-DA scores plot for 115 quantified lipid molecular species revealed a clear separation of the hepatic lipid profile of sedentary from recovering mice, but not from mice immediately after running. 21 lipid species were considered to be most responsible for the difference in the hepatic lipid profiles, including 17 triacylglycerides (TG, one lysophosphatidylcholine (LPC and three phosphatidylcholines (PC. TG species were found to be more abundant in the recovery phase, while PC species were decreased. The degree of accumulation of individual TG species correlated well with the amount of theoretical energy stored whereas no increase was found for TG species containing only saturated or one monounsaturated fatty acid. Total liver TG content as assayed by an enzymatic method was increased to 163% in the recovery phase, while it was significantly decreased in skeletal muscle by the exercise bout and remained less in the recovery phase. Results from fasted and refed mice indicate that fasting-induced lipolysis was associated with a pronounced accumulation of hepatic TG, which is reversed by refeeding for 5 h. Thus food intake per se did not elevate hepatic TG. CONCLUSION: These data indicate that high availability of FFA induced by endurance exercise or fasting resulted in a transient hepatic TG accumulation, while muscle TG content was decreased during exercise presumably due to increased muscle fatty

  10. Down-regulation of the caffeic acid O-methyltransferase gene in switchgrass reveals a novel monolignol analog

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    Tschaplinski Timothy J

    2012-09-01

    Full Text Available Abstract Background Down-regulation of the caffeic acid 3-O-methyltransferase EC 2.1.1.68 (COMT gene in the lignin biosynthetic pathway of switchgrass (Panicum virgatum resulted in cell walls of transgenic plants releasing more constituent sugars after pretreatment by dilute acid and treatment with glycosyl hydrolases from an added enzyme preparation and from Clostridium thermocellum. Fermentation of both wild-type and transgenic switchgrass after milder hot water pretreatment with no water washing showed that only the transgenic switchgrass inhibited C. thermocellum. Gas chromatography–mass spectrometry (GCMS-based metabolomics were undertaken on cell wall aqueous extracts to determine the nature of the microbial inhibitors. Results GCMS confirmed the increased concentration of a number of phenolic acids and aldehydes that are known inhibitors of microbial fermentation. Metabolomic analyses of the transgenic biomass additionally revealed the presence of a novel monolignol-like metabolite, identified as trans-3, 4-dimethoxy-5-hydroxycinnamyl alcohol (iso-sinapyl alcohol in both non-pretreated, as well as hot water pretreated samples. iso-Sinapyl alcohol and its glucoside were subsequently generated by organic synthesis and the identity of natural and synthetic materials were confirmed by mass spectrometric and NMR analyses. The additional novel presence of iso-sinapic acid, iso-sinapyl aldehyde, and iso-syringin suggest the increased activity of a para-methyltransferase, concomitant with the reduced COMT activity, a strict meta-methyltransferase. Quantum chemical calculations were used to predict the most likely homodimeric lignans generated from dehydration reactions, but these products were not evident in plant samples. Conclusions Down-regulation of COMT activity in switchgrass resulted in the accumulation of previously undetected metabolites resembling sinapyl alcohol and its related metabolites, but that are derived from para

  11. Metabonomics reveals drastic changes in anti-inflammatory/pro-resolving polyunsaturated fatty acids-derived lipid mediators in leprosy disease.

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    Julio J Amaral

    Full Text Available Despite considerable efforts over the last decades, our understanding of leprosy pathogenesis remains limited. The complex interplay between pathogens and hosts has profound effects on host metabolism. To explore the metabolic perturbations associated with leprosy, we analyzed the serum metabolome of leprosy patients. Samples collected from lepromatous and tuberculoid patients before and immediately after the conclusion of multidrug therapy (MDT were subjected to high-throughput metabolic profiling. Our results show marked metabolic alterations during leprosy that subside at the conclusion of MDT. Pathways showing the highest modulation were related to polyunsaturated fatty acid (PUFA metabolism, with emphasis on anti-inflammatory, pro-resolving omega-3 fatty acids. These results were confirmed by eicosanoid measurements through enzyme-linked immunoassays. Corroborating the repertoire of metabolites altered in sera, metabonomic analysis of skin specimens revealed alterations in the levels of lipids derived from lipase activity, including PUFAs, suggesting a high lipid turnover in highly-infected lesions. Our data suggest that omega-6 and omega-3, PUFA-derived, pro-resolving lipid mediators contribute to reduced tissue damage irrespectively of pathogen burden during leprosy disease. Our results demonstrate the utility of a comprehensive metabonomic approach for identifying potential contributors to disease pathology that may facilitate the development of more targeted treatments for leprosy and other inflammatory diseases.

  12. Metabonomics Reveals Drastic Changes in Anti-Inflammatory/Pro-Resolving Polyunsaturated Fatty Acids-Derived Lipid Mediators in Leprosy Disease

    Science.gov (United States)

    Amaral, Julio J.; Antunes, Luis Caetano M.; de Macedo, Cristiana S.; Mattos, Katherine A.; Han, Jun; Pan, Jingxi; Candéa, André L. P.; Henriques, Maria das Graças M. O.; Ribeiro-Alves, Marcelo; Borchers, Christoph H.; Sarno, Euzenir N.; Bozza, Patrícia T.; Finlay, B. Brett; Pessolani, Maria Cristina V.

    2013-01-01

    Despite considerable efforts over the last decades, our understanding of leprosy pathogenesis remains limited. The complex interplay between pathogens and hosts has profound effects on host metabolism. To explore the metabolic perturbations associated with leprosy, we analyzed the serum metabolome of leprosy patients. Samples collected from lepromatous and tuberculoid patients before and immediately after the conclusion of multidrug therapy (MDT) were subjected to high-throughput metabolic profiling. Our results show marked metabolic alterations during leprosy that subside at the conclusion of MDT. Pathways showing the highest modulation were related to polyunsaturated fatty acid (PUFA) metabolism, with emphasis on anti-inflammatory, pro-resolving omega-3 fatty acids. These results were confirmed by eicosanoid measurements through enzyme-linked immunoassays. Corroborating the repertoire of metabolites altered in sera, metabonomic analysis of skin specimens revealed alterations in the levels of lipids derived from lipase activity, including PUFAs, suggesting a high lipid turnover in highly-infected lesions. Our data suggest that omega-6 and omega-3, PUFA-derived, pro-resolving lipid mediators contribute to reduced tissue damage irrespectively of pathogen burden during leprosy disease. Our results demonstrate the utility of a comprehensive metabonomic approach for identifying potential contributors to disease pathology that may facilitate the development of more targeted treatments for leprosy and other inflammatory diseases. PMID:23967366

  13. Salts of hexamethylenetetramine with organic acids: Enhanced anomeric interactions with a lowering of molecular symmetry revealed by crystal structures

    Science.gov (United States)

    Chandrasekhar, Sosale; Mukherjee, Somnath

    2015-02-01

    The hexamethylenetetramine (HMT) framework displays interesting stereoelectronic interactions of the anomeric type. In the highly symmetrical parent system, the nitrogen centres act as both donors and acceptors. Protonation lowers symmetry and also leads to an enhancement of the anomeric interaction around the protonated centre. X-ray diffraction crystal structures of four derivatives of HMT - with succinic, (DL)-malic, phthalic and 4-hydroxybenzoic acids - reveal significant trends. (The first three form well-defined salts, 4-hydroxybenzoic acid forming a co-crystalline compound.) Each molecular structure is essentially characterised by a major anomeric interaction involving the protonated centre as acceptor. In two cases (succinic and 4-hydroxybenzoic), secondary protonation leads to a weaker anomeric interaction site that apparently competes with the dominant one. Bond length changes indicate that the anomeric interaction decreases as malic > phthalic > succinic > 4-hydroxybenzoic, which correlates with the degree of proton transfer to the nitrogen centre. Along with other bond length and angle changes, the results offer insight into the applicability of the antiperiplanar lone pair hypothesis (ALPH) in a rigid system.

  14. Carbon and Nitrogen Isotopes from Top Predator Amino Acids Reveal Rapidly Shifting Ocean Biochemistry in the Outer California Current

    Science.gov (United States)

    Ruiz-Cooley, Rocio I.; Koch, Paul L.; Fiedler, Paul C.; McCarthy, Matthew D.

    2014-01-01

    Climatic variation alters biochemical and ecological processes, but it is difficult both to quantify the magnitude of such changes, and to differentiate long-term shifts from inter-annual variability. Here, we simultaneously quantify decade-scale isotopic variability at the lowest and highest trophic positions in the offshore California Current System (CCS) by measuring δ15N and δ13C values of amino acids in a top predator, the sperm whale (Physeter macrocephalus). Using a time series of skin tissue samples as a biological archive, isotopic records from individual amino acids (AAs) can reveal the proximate factors driving a temporal decline we observed in bulk isotope values (a decline of ≥1 ‰) by decoupling changes in primary producer isotope values from those linked to the trophic position of this toothed whale. A continuous decline in baseline (i.e., primary producer) δ15N and δ13C values was observed from 1993 to 2005 (a decrease of ∼4‰ for δ15N source-AAs and 3‰ for δ13C essential-AAs), while the trophic position of whales was variable over time and it did not exhibit directional trends. The baseline δ15N and δ13C shifts suggest rapid ongoing changes in the carbon and nitrogen biogeochemical cycling in the offshore CCS, potentially occurring at faster rates than long-term shifts observed elsewhere in the Pacific. While the mechanisms forcing these biogeochemical shifts remain to be determined, our data suggest possible links to natural climate variability, and also corresponding shifts in surface nutrient availability. Our study demonstrates that isotopic analysis of individual amino acids from a top marine mammal predator can be a powerful new approach to reconstructing temporal variation in both biochemical cycling and trophic structure. PMID:25329915

  15. Design and exploration of novel boronic acid inhibitors reveals important interactions with a clavulanic acid-resistant sulfhydryl-variable (SHV) β-lactamase.

    Science.gov (United States)

    Winkler, Marisa L; Rodkey, Elizabeth A; Taracila, Magdalena A; Drawz, Sarah M; Bethel, Christopher R; Papp-Wallace, Krisztina M; Smith, Kerri M; Xu, Yan; Dwulit-Smith, Jeffrey R; Romagnoli, Chiara; Caselli, Emilia; Prati, Fabio; van den Akker, Focco; Bonomo, Robert A

    2013-02-14

    Inhibitor resistant (IR) class A β-lactamases pose a significant threat to many current antibiotic combinations. The K234R substitution in the SHV β-lactamase, from Klebsiella pneumoniae , results in resistance to ampicillin/clavulanate. After site-saturation mutagenesis of Lys-234 in SHV, microbiological and biochemical characterization of the resulting β-lactamases revealed that only -Arg conferred resistance to ampicillin/clavulanate. X-ray crystallography revealed two conformations of Arg-234 and Ser-130 in SHV K234R. The movement of Ser-130 is the principal cause of the observed clavulanate resistance. A panel of boronic acid inhibitors was designed and tested against SHV-1 and SHV K234R. A chiral ampicillin analogue was discovered to have a 2.4 ± 0.2 nM K(i) for SHV K234R; the chiral ampicillin analogue formed a more complex hydrogen-bonding network in SHV K234R vs SHV-1. Consideration of the spatial position of Ser-130 and Lys-234 and this hydrogen-bonding network will be important in the design of novel antibiotics targeting IR β-lactamases.

  16. Distinct Anaerobic Bacterial Consumers of Cellobiose-Derived Carbon in Boreal Fens with Different CO2/CH4 Production Ratios.

    Science.gov (United States)

    Juottonen, Heli; Eiler, Alexander; Biasi, Christina; Tuittila, Eeva-Stiina; Yrjälä, Kim; Fritze, Hannu

    2017-02-15

    Northern peatlands in general have high methane (CH4) emissions, but individual peatlands show considerable variation as CH4 sources. Particularly in nutrient-poor peatlands, CH4 production can be low and exceeded by carbon dioxide (CO2) production from unresolved anaerobic processes. To clarify the role anaerobic bacterial degraders play in this variation, we compared consumers of cellobiose-derived carbon in two fens differing in nutrient status and the ratio of CO2 to CH4 produced. After [(13)C]cellobiose amendment, the mesotrophic fen produced equal amounts of CH4 and CO2 The oligotrophic fen had lower CH4 production but produced 3 to 59 times more CO2 than CH4 RNA stable-isotope probing revealed that in the mesotrophic fen with higher CH4 production, cellobiose-derived carbon was mainly assimilated by various recognized fermenters of Firmicutes and by Proteobacteria The oligotrophic peat with excess CO2 production revealed a wider variety of cellobiose-C consumers, including Firmicutes and Proteobacteria, but also more unconventional degraders, such as Telmatobacter-related Acidobacteria and subphylum 3 of Verrucomicrobia Prominent and potentially fermentative Planctomycetes and Chloroflexi did not appear to process cellobiose-C. Our results show that anaerobic degradation resulting in different levels of CH4 production can involve distinct sets of bacterial degraders. By distinguishing cellobiose degraders from the total community, this study contributes to defining anaerobic bacteria that process cellulose-derived carbon in peat. Several of the identified degraders, particularly fermenters and potential Fe(III) or humic substance reducers in the oligotrophic peat, represent promising candidates for resolving the origin of excess CO2 production in peatlands.

  17. Revealing biogenic sulfuric acid corrosion in sludge digesters: detection of sulfur-oxidizing bacteria within full-scale digesters.

    Science.gov (United States)

    Huber, B; Drewes, J E; Lin, K C; König, R; Müller, E

    2014-01-01

    Biogenic sulfuric acid corrosion (BSA) is a costly problem affecting both sewerage infrastructure and sludge handling facilities such as digesters. The aim of this study was to verify BSA in full-scale digesters by identifying the microorganisms involved in the concrete corrosion process, that is, sulfate-reducing (SRB) and sulfur-oxidizing bacteria (SOB). To investigate the SRB and SOB communities, digester sludge and biofilm samples were collected. SRB diversity within digester sludge was studied by applying polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) targeting the dsrB-gene (dissimilatory sulfite reductase beta subunit). To reveal SOB diversity, cultivation dependent and independent techniques were applied. The SRB diversity studies revealed different uncultured SRB, confirming SRB activity and H2S production. Comparable DGGE profiles were obtained from the different sludges, demonstrating the presence of similar SRB species. By cultivation, three pure SOB strains from the digester headspace were obtained including Acidithiobacillus thiooxidans, Thiomonas intermedia and Thiomonas perometabolis. These organisms were also detected with PCR-DGGE in addition to two new SOB: Thiobacillus thioparus and Paracoccus solventivorans. The SRB and SOB responsible for BSA were identified within five different digesters, demonstrating that BSA is a problem occurring not only in sewer systems but also in sludge digesters. In addition, the presence of different SOB species was successfully associated with the progression of microbial corrosion.

  18. Understanding the Groundwater Hydrology of a Geographically-Isolated Prairie Fen: Implications for Conservation.

    Science.gov (United States)

    Sampath, Prasanna Venkatesh; Liao, Hua-Sheng; Curtis, Zachary Kristopher; Doran, Patrick J; Herbert, Matthew E; May, Christopher A; Li, Shu-Guang

    2015-01-01

    The sources of water and corresponding delivery mechanisms to groundwater-fed fens are not well understood due to the multi-scale geo-morphologic variability of the glacial landscape in which they occur. This lack of understanding limits the ability to effectively conserve these systems and the ecosystem services they provide, including biodiversity and water provisioning. While fens tend to occur in clusters around regional groundwater mounds, Ives Road Fen in southern Michigan is an example of a geographically-isolated fen. In this paper, we apply a multi-scale groundwater modeling approach to understand the groundwater sources for Ives Road fen. We apply Transition Probability geo-statistics on more than 3000 well logs from a state-wide water well database to characterize the complex geology using conditional simulations. We subsequently implement a 3-dimensional reverse particle tracking to delineate groundwater contribution areas to the fen. The fen receives water from multiple sources: local recharge, regional recharge from an extensive till plain, a regional groundwater mound, and a nearby pond. The regional sources deliver water through a tortuous, 3-dimensional "pipeline" consisting of a confined aquifer lying beneath an extensive clay layer. Water in this pipeline reaches the fen by upwelling through openings in the clay layer. The pipeline connects the geographically-isolated fen to the same regional mound that provides water to other fen clusters in southern Michigan. The major implication of these findings is that fen conservation efforts must be expanded from focusing on individual fens and their immediate surroundings, to studying the much larger and inter-connected hydrologic network that sustains multiple fens.

  19. Fenómeno de Koebner The Koebner phenomenon

    Directory of Open Access Journals (Sweden)

    R E Achenbach

    2011-09-01

    Full Text Available Descrito en 1871 por Heinrich Koebner, su fenómeno es uno de los más conocidos en la Dermatología. Koebner lo describe en un paciente con psoriasis que sufrió escoriaciones múltiples y una mordedura de caballo. Su figura fue una de las más destacadas en la Dermatología del siglo 19. Se revisa la lista de entidades con fenómeno Koebner y sus variantes, los tipos de injurias y su patogenia.First described in 1871, the Koebner phenomenon is one of the most well-known entities in dermatology. Heinrich Koebner is credited with the first adequate description of this peculiar disposition of psoriatic skin. He was one of the outstanding dermatologists of the 19th Century and reported the formation of psoriasiform lesions in uninvolved skin after excoriations and horse bites. Types of Koebner response, a list of injuries capable to produce it and a review of the pathogenesis are reviewed.

  20. Fenótipos clínicos de asma grave Clinical phenotypes of severe asthma

    Directory of Open Access Journals (Sweden)

    Roseliane de Souza Araújo Alves

    2008-09-01

    Full Text Available OBJETIVO: Estabelecer os fenótipos clínicos em portadores de asma grave. MÉTODOS: Foram estudados, retrospectivamente, 111 pacientes em um ambulatório especializado. Os pacientes foram avaliados e acompanhados de maneira sistemática, estabelecendo-se ao final do acompanhamento a adesão e o controle ou não da doença por dados clínicos e funcionais. A resistência ao tratamento foi definida como o não preenchimento, ao final do acompanhamento, por pelo menos seis meses, dos critérios de controle de asma, apesar do uso correto e adesão à medicação. Os fenótipos foram determinados por análise fatorial e comparados por testes diversos. RESULTADOS: Ao final, 88 pacientes foram considerados aderentes e 23 não aderentes. Por análise fatorial do grupo aderente, quatro fenótipos foram determinados: o fenótipo 1 (28 pacientes, formado pelos pacientes resistentes ao tratamento, com maior freqüência de sintomas noturnos, maior número de exacerbações e uso mais freqüente de broncodilatador de resgate; o fenótipo 2 (48 pacientes, formado pelos pacientes com obstrução persistente, com menores valores de relação volume expiratório forçado no primeiro segundo/capacidade vital forçada na avaliação inicial, idade mais avançada e maior tempo de doença; o fenótipo 3 (42 pacientes, representa os pacientes com rinossinusite alérgica, sendo constituído de não fumantes com obstrução predominantemente reversível; e o fenótipo 4 (15 pacientes, formado por casos com história de intolerância à aspirina associado à asma quase fatal. CONCLUSÕES: Um número significativo de portadores de ama grave não adere ao tratamento. Muitos pacientes com asma grave têm obstrução irreversível, mas o fenótipo clínico mais relevante é constituído pelos pacientes resistentes ao tratamento habitual.OBJECTIVE: To characterize clinical phenotypes of severe asthma. METHODS: A total of 111 patients were retrospectively evaluated at a

  1. Site-directed mutagenesis of HgcA and HgcB reveals amino acid residues important for mercury methylation.

    Science.gov (United States)

    Smith, Steven D; Bridou, Romain; Johs, Alexander; Parks, Jerry M; Elias, Dwayne A; Hurt, Richard A; Brown, Steven D; Podar, Mircea; Wall, Judy D

    2015-05-01

    Methylmercury is a potent neurotoxin that is produced by anaerobic microorganisms from inorganic mercury by a recently discovered pathway. A two-gene cluster, consisting of hgcA and hgcB, encodes two of the proteins essential for this activity. hgcA encodes a corrinoid protein with a strictly conserved cysteine proposed to be the ligand for cobalt in the corrinoid cofactor, whereas hgcB encodes a ferredoxin-like protein thought to be an electron donor to HgcA. Deletion of either gene eliminates mercury methylation by the methylator Desulfovibrio desulfuricans ND132. Here, site-directed mutants of HgcA and HgcB were constructed to determine amino acid residues essential for mercury methylation. Mutations of the strictly conserved residue Cys93 in HgcA, the proposed ligand for the corrinoid cobalt, to Ala or Thr completely abolished the methylation capacity, but a His substitution produced measurable methylmercury. Mutations of conserved amino acids near Cys93 had various impacts on the methylation capacity but showed that the structure of the putative "cap helix" region harboring Cys93 is crucial for methylation function. In the ferredoxin-like protein HgcB, only one of two conserved cysteines found at the C terminus was necessary for methylation, but either cysteine sufficed. An additional, strictly conserved cysteine, Cys73, was also determined to be essential for methylation. This study supports the previously predicted importance of Cys93 in HgcA for methylation of mercury and reveals additional residues in HgcA and HgcB that facilitate the production of this neurotoxin.

  2. Novel and Unexpected Microbial Diversity in Acid Mine Drainage in Svalbard (78° N, Revealed by Culture-Independent Approaches

    Directory of Open Access Journals (Sweden)

    Antonio García-Moyano

    2015-10-01

    Full Text Available Svalbard, situated in the high Arctic, is an important past and present coal mining area. Dozens of abandoned waste rock piles can be found in the proximity of Longyearbyen. This environment offers a unique opportunity for studying the biological control over the weathering of sulphide rocks at low temperatures. Although the extension and impact of acid mine drainage (AMD in this area is known, the native microbial communities involved in this process are still scarcely studied and uncharacterized. Several abandoned mining areas were explored in the search for active AMD and a culture-independent approach was applied with samples from two different runoffs for the identification and quantification of the native microbial communities. The results obtained revealed two distinct microbial communities. One of the runoffs was more extreme with regards to pH and higher concentration of soluble iron and heavy metals. These conditions favored the development of algal-dominated microbial mats. Typical AMD microorganisms related to known iron-oxidizing bacteria (Acidithiobacillus ferrivorans, Acidobacteria and Actinobacteria dominated the bacterial community although some unexpected populations related to Chloroflexi were also significant. No microbial mats were found in the second area. The geochemistry here showed less extreme drainage, most likely in direct contact with the ore under the waste pile. Large deposits of secondary minerals were found and the presence of iron stalks was revealed by microscopy analysis. Although typical AMD microorganisms were also detected here, the microbial community was dominated by other populations, some of them new to this type of system (Saccharibacteria, Gallionellaceae. These were absent or lowered in numbers the farther from the spring source and they could represent native populations involved in the oxidation of sulphide rocks within the waste rock pile. This environment appears thus as a highly interesting

  3. In Vivo Screening Using Transgenic Zebrafish Embryos Reveals New Effects of HDAC Inhibitors Trichostatin A and Valproic Acid on Organogenesis.

    Directory of Open Access Journals (Sweden)

    Ling Li

    Full Text Available The effects of endocrine disrupting chemicals (EDCs on reproduction are well known, whereas their developmental effects are much less characterized. However, exposure to endocrine disruptors during organogenesis may lead to deleterious and permanent problems later in life. Zebrafish (Danio rerio transgenic lines expressing the green fluorescent protein (GFP in specific organs and tissues are powerful tools to uncover developmental defects elicited by EDCs. Here, we used seven transgenic lines to visualize in vivo whether a series of EDCs and other pharmaceutical compounds can alter organogenesis in zebrafish. We used transgenic lines expressing GFP in pancreas, liver, blood vessels, inner ear, nervous system, pharyngeal tooth and pectoral fins. This screen revealed that four of the tested chemicals have detectable effects on different organs, which shows that the range of effects elicited by EDCs is wider than anticipated. The endocrine disruptor tetrabromobisphenol-A (TBBPA, as well as the three drugs diclofenac, trichostatin A (TSA and valproic acid (VPA induced abnormalities in the embryonic vascular system of zebrafish. Moreover, TSA and VPA induced specific alterations during the development of pancreas, an observation that was confirmed by in situ hybridization with specific markers. Developmental delays were also induced by TSA and VPA in the liver and in pharyngeal teeth, resulting in smaller organ size. Our results show that EDCs can induce a large range of developmental alterations during embryogenesis of zebrafish and establish GFP transgenic lines as powerful tools to screen for EDCs effects in vivo.

  4. Throughflow as a determining factor for habitat contiguity in a near-natural fen

    Science.gov (United States)

    van Loon, A. H.; Schot, P. P.; Griffioen, J.; Bierkens, M. F. P.; Batelaan, O.; Wassen, M. J.

    2009-12-01

    SummaryKnowledge of the hydrological mechanisms that underlie stable plant communities within natural fens is essential for the improvement of current fen restoration and conservation strategies. In this study, steady-state groundwater modelling was performed to quantify the impact of throughflow mechanisms on the presence of exfiltrated, alkaline groundwater across a near-natural fen in the Biebrza River catchment (Poland). Alkaline groundwater is considered essential for the existence of low-productive fen plants. The results indicate that throughflow redistributes exfiltrated groundwater, mixed with locally infiltrated precipitation, in various concentrations across the fen. The throughflow model provides an explanation for the major patterns in the plant alliances that have a preference for minerotrophic or ombrotrophic habitat conditions. These patterns could not be reproduced with groundwater models that did not account for the existence of throughflow on a regional scale. We conclude that throughflow (1) enables a spatially contiguous supply of exfiltrated groundwater across fens, and thereby (2) facilitates abiotic conditions suitable for fen plants outside the zones that are directly supplied by exfiltrated groundwater. These new insights into landscape hydrological mechanisms that drive abiotic conditions within natural fens necessitate the reprioritisation of current hydrological fen restoration strategies.

  5. Nuevos fenómenos en erupciones cometarias

    Science.gov (United States)

    Silva, A.

    Se discuten aquí tres procesos físicos novedosos encontrados en la actividad de cometas: 1) El rol de una distribución de granos de hielo como fuente extendida de H2O en la coma, 2) El efecto de una discontinuidad en el plasma cometario, llamada Cometopausa, sobre la excitación del radical OH , y 3) La actividad por erupciones a grandes distancias heliocéntricas (r > 5 AU). Con respecto a 1) y 2), se presentan modelos que ajustan bien con las observaciones. En cuanto a 3), se presentan explicaciones posibles al fenómeno, y se trata el interesante caso de Chirón 2060, basándose en observaciones propias tomadas desde el CASLEO y datos anteriores.

  6. N and P addition inhibits growth of rich fen bryophytes

    DEFF Research Database (Denmark)

    Andersen, Dagmar Kappel; Ejrnæs, Rasmus; Riis, Tenna

    2016-01-01

    vernicosus and paludella squarrosa) rich fen bryophytes were grown in mixed culture and subjected to rainwater or groundwater and three levels of N (0, 1 and 3 mg N L-1) and P (0, 0.05 and 0.1 mg P NL-1). All species responded negatively to higher N-levels and three of four species responded negatively...... to rainwater and higher P-levels. C. cuspidata had highest relative growth rate in all treatments, and the infrequently occurringrare species had lower relative growth rate and were more negatively affected by high levels of N than the frequently occurringcommon species. A negative effect of rainwater seemed...... to be caused by higher background levels of N in rainwater compared to groundwater rather than a pH-effect per se. We found a negative effect of high initial bryophyte density in three of four species indicating density dependent inhibition between species.We suggest that maintenance of oligotrophic conditions...

  7. A fully validated GC-TOF-MS method for the quantification of fatty acids revealed alterations in the metabolic profile of fatty acids after smoking cessation.

    Science.gov (United States)

    Goettel, Michael; Niessner, Reinhard; Pluym, Nikola; Scherer, Gerhard; Scherer, Max

    2017-01-15

    We developed and validated an efficient and robust method for the simultaneous quantification of 44 fatty acid species in human plasma via GC-TOF-MS. The method is characterized by its robustness, accuracy and precision covering a wide range of fatty acid species with various saturation degrees including short chain fatty acids (beginning with FA 4:0) and long chain fatty acids (up to FA 32:0). The fatty acids were methylated prior to analyses and subsequently detected as fatty acid methyl esters by means of GC-TOF-MS. A highly substituted polar column allowed the separation of geometrical and positional isomers of fatty acid species. The method was applied to plasma samples of a strictly diet controlled clinical smoking cessation study including 39 smokers followed over the course of three months after having quit. Statistical significant alterations within the fatty acid profile were observed when comparing the baseline (subjects still smoking) with one week, one month and three months of smoking cessation. After 3 months of smoking cessation, a partial recovery of alterations in the fatty acid profile evoked by smoking was observed. In conclusion, the developed fatty acid profiling method using GC-TOF-MS has proven as a reliable tool for the quantitative determination of 44 individual fatty acid species within clinical studies.

  8. Elemental microchemistry, fatty acid profile and geometric morphometrics signatures of goose barnacles (Pollicipes pollicipes reveal their place of origin

    Directory of Open Access Journals (Sweden)

    Rui Albuquerque

    2014-06-01

    Full Text Available Seafood plays an important role in the socioeconomic, gastronomy and cultural heritage of Portuguese coastal communities. In the Iberian Peninsula, the goose barnacle Pollicipes pollicipes is the intertidal biological resource most heavily exploited by man, resulting on overexploitation of stocks. In the MPA of BNR P.pollicipes harvesting is however strictly regulated, making it a good example of marine resources management. Analytical methods able to identify the origin of goose barnacle would be an important tool to help the management of the trade. For such purpose, we investigated whether P. pollicipes have site-specific differences based on its elemental microchemistry (EM, fatty acid profile (FA and capitulum shape (CS. The analysis was performed on specimens collected from 3 sites in the BNR and 7 along a 300 km stretch of the Portuguese coast. For each individual we analysed the largest lateral shell for EM using ICP-MS, the FA content of the muscle using GC-FID, and the CS using geometric morphometrics. Discriminant function analyses (DFA for both EM and FA separately provided a high reclassification success (77.6% and 99% respectively, of cross-validated cases correctly classified, while for EM combined with FA allowed for a 100% reclassification success. DFA analysis based only on CS, revealed a low classification success (29.6%. These results show that EM and FA signatures can be a powerful tool to infer goose barnacles origin. Such “fingerprinting” approach can be used to track and identify goose barnacles origin, helping in establishing an origin certificate and increasing the potential value of biological resources from Portuguese MPAs.

  9. Relationship between acid tolerance and cell membrane in Bifidobacterium, revealed by comparative analysis of acid-resistant derivatives and their parental strains grown in medium with and without Tween 80.

    Science.gov (United States)

    Yang, Xu; Hang, Xiaomin; Zhang, Min; Liu, Xianglong; Yang, Hong

    2015-06-01

    The acid tolerance is particularly important for bifidobacteria to function as probiotics because they usually encounter acidic environments in food products and gastrointestinal tract passage. In this study, two acid-resistant derivatives Bifidobacterium longum JDY1017dpH and Bifidobacterium breve BB8dpH, which displayed a stable acid-resistant phenotype, were generated. The relationship between acid tolerance and cell membrane was investigated by comparing the two acid-resistant derivatives and their parental strains grown in medium with and without Tween 80. The fold increase in acid tolerance of the two acid-resistant derivatives relative to their parental strains was much higher when cells were grown in medium with Tween 80 (10(4) ~ 10(5)-fold) than without Tween 80 (181- and 245-fold). Moreover, when cells were grown in medium with Tween 80, the two acid-resistant derivatives exhibited more C18:1 and cycC19:0, higher mean fatty acid chain length, lower membrane fluidity, and higher expression of cfa gene encoding cyclopropane fatty acid synthase than their parental strains. No significant differences in cell membrane were observed between the two acid-resistant derivatives and their parental strains when cells were grown in medium without Tween 80. The present study revealed that, when cells were grown in medium with Tween 80, the significant fold increase in acid tolerance of the two acid-resistant derivatives was mainly ascribed to the pronounced changes in cell membrane compared with their parental strains. Results presented here could provide a basis for developing new strategies of cell membrane modification to enhance acid tolerance in bifidobacteria.

  10. Development of hydraulic properties and nitrate turnover processes in minerotrophic fen soil on differnet scales

    Science.gov (United States)

    Kleimeier, Christian; Lennartz, Bernd

    2014-05-01

    Generally, it is recommended to remove the uppermost highly degraded peat layer from fens prior to rewetting to eliminate a potential source of organic pollutants for downstream water bodies. We investigated this material as a potential medium for denitrifying filters to further use the organic material. We are aiming to remove nitrate from tile drainage runoff at the outlet drainage dominated catchments to fullfill the requirements of the European Water Framework Directive. In a lysimeter scale long term mesocosm experiments we were aiming to reveal the peats behavior after disturbing and rewetting under constant flow conditions. Tracer experiments revealed a restructuring of the peat ending up at 20/80 percentage of mobile immobile pore volume. Additionally we observed the nitrate turnover. The turnover rate was determined by the hydraulic load. Absolute turnover rates were equal at lower and higher concentrations as well as flow rates, whereas the turnover reached higher percentages at lower concentrations. To further reveal the nitrate turnover processes flow through rector experiments were conducted in an anaerobic environment. We found that strongly reducing conditions can be created in peat even at the presence of nitrate. Thus we can conclude that the minerotrophic peat with its high iron and sulfur concentrations also enables autotrophic denitrification oxidizing iron and sulfur. While the conditions are favorable to re-reduce iron and sulfur,thus an electron shuttling system developed transporting electrons from the organic material as initial e- donor to nitrate as terminal e- acceptor.

  11. Pseudomonas lini Strain ZBG1 Revealed Carboxylic Acid Utilization and Copper Resistance Features Required for Adaptation to Vineyard Soil Environment: A Draft Genome Analysis

    Science.gov (United States)

    Chan, Kok-Gan; Chong, Teik-Min; Adrian, Tan-Guan-Sheng; Kher, Heng Leong; Grandclément, Catherine; Faure, Denis; Yin, Wai-Fong; Dessaux, Yves; Hong, Kar-Wai

    2016-01-01

    Pseudomonas lini strain ZBG1 was isolated from the soil of vineyard in Zellenberg, France and the draft genome was reported in this study. Bioinformatics analyses of the genome revealed presence of genes encoding tartaric and malic acid utilization as well as copper resistance that correspond to the adaptation this strain in vineyard soil environment. PMID:27512520

  12. Nutrient imitations in an extant and drained poor fen : implications for restoration

    NARCIS (Netherlands)

    VanDuren, IC; Boeye, D; Grootjans, AP

    1997-01-01

    In a species-rich poor fen (Caricetum nigrae) and a species-poor drained fen, the difference in nutrient limitation of the vegetation was assessed in a full-factorial fertilization experiment with N, P and K. The results were compared to the nutrient ratios of plant material and to chemical analysis

  13. Microbial activity and community structure in two drained fen soils in the Ljubljana Marsh

    NARCIS (Netherlands)

    Kraigher, Barbara; Stres, Blaz; Hacin, Janez; Ausec, Luka; Mahne, Ivan; van Elsas, Jan D.; Mandic-Mulec, Ines

    2006-01-01

    Fen peatlands are specific wetland ecosystems containing high soil organic carbon (SOC). There is a general lack of knowledge about the microbial communities that abound in these systems. We examined the microbial activity and community structure in two fen soils differing in SOC content sampled fro

  14. Effects of salinity on growth of plant species from terrestrializing fens

    NARCIS (Netherlands)

    Stofberg, S.F.; Klimkovska, A.; Paulissen, M.P.C.P.; Witte, J.Ph.M.; Zee, van der S.E.A.T.M.

    2015-01-01

    Terrestrializing lowland fens may be temporarily exposed to elevated surface water salinity, which may have serious consequences for nature conservation. We investigated the response of five fresh water fen plant species to elevated salinity. In a controlled greenhouse experiment, these species were

  15. Remotely sensed hydrological isolation : A key factor predicting plant species distribution in fens

    NARCIS (Netherlands)

    Sanders, M.E.

    1999-01-01

    In fens the species composition, vegetation structure and succession rate are determined by vegetation management and water chemistry, particularly by the base status and nutrient status. Base-rich and nutrient-rich surface water causes fens to become eutrophied, which leads to an increased biomass

  16. Throughflow as a determining factor for habitat contiguity in a near-natural fen

    NARCIS (Netherlands)

    Loon, A.H. van; Schot, P.P.; Griffioen, J.; Bierkens, M.F.P.; Batelaan, O.; Wassen, M.J.

    2009-01-01

    Knowledge of the hydrological mechanisms that underlie stable plant communities within natural fens is essential for the improvement of current fen restoration and conservation strategies. In this study, steady-state groundwater modelling was performed to quantify the impact of throughflow mechanism

  17. Stream characteristics and their implications for the protection of riparian fens and meadows

    DEFF Research Database (Denmark)

    Baattrup-Pedersen, A.; Larsen, S.E.; Andersen, Peter Mejlhede

    2011-01-01

    1. Running waters, including associated riparian areas, are embraced by international legal frameworks outlining targets for the preservation, protection and improvement of the quality of the environment. Interactions between stream and river processes and riparian habitats have not received much......-based classification model was used to translate species lists into a standardised interpretation of habitat types protected by the HD in Denmark. 3. No size dependency was found regarding the distribution of fen and meadow vegetation. Instead, the distribution of fen and meadow vegetation was strongly affected...... of riparian areas, affecting conditions needed to sustain protected fen and meadow communities. 4. We also found that water chemistry strongly influenced the occurrence of fen and meadow vegetation in riparian areas. The probability of finding fen and meadow vegetation was reduced when total phosphorus (TP...

  18. Isolation and characterization of a low phytic acid rice mutant reveals a mutation in the rice orthologue of maize mik.

    Science.gov (United States)

    Using a forward genetics approach, we isolated two independent low phytic acid (lpa) rice mutants, N15-186 and N15-375. Both mutants are caused by single gene, recessive non-lethal mutations which result in approximately 75% (N15-186) and 43% (N15-375) reductions in seed phytic acid (inositol hexaki...

  19. Mutational Studies on Resurrected Ancestral Proteins Reveal Conservation of Site-Specific Amino Acid Preferences throughout Evolutionary History

    Science.gov (United States)

    Risso, Valeria A.; Manssour-Triedo, Fadia; Delgado-Delgado, Asunción; Arco, Rocio; Barroso-delJesus, Alicia; Ingles-Prieto, Alvaro; Godoy-Ruiz, Raquel; Gavira, Jose A.; Gaucher, Eric A.; Ibarra-Molero, Beatriz; Sanchez-Ruiz, Jose M.

    2015-01-01

    Local protein interactions (“molecular context” effects) dictate amino acid replacements and can be described in terms of site-specific, energetic preferences for any different amino acid. It has been recently debated whether these preferences remain approximately constant during evolution or whether, due to coevolution of sites, they change strongly. Such research highlights an unresolved and fundamental issue with far-reaching implications for phylogenetic analysis and molecular evolution modeling. Here, we take advantage of the recent availability of phenotypically supported laboratory resurrections of Precambrian thioredoxins and β-lactamases to experimentally address the change of site-specific amino acid preferences over long geological timescales. Extensive mutational analyses support the notion that evolutionary adjustment to a new amino acid may occur, but to a large extent this is insufficient to erase the primitive preference for amino acid replacements. Generally, site-specific amino acid preferences appear to remain conserved throughout evolutionary history despite local sequence divergence. We show such preference conservation to be readily understandable in molecular terms and we provide crystallographic evidence for an intriguing structural-switch mechanism: Energetic preference for an ancestral amino acid in a modern protein can be linked to reorganization upon mutation to the ancestral local structure around the mutated site. Finally, we point out that site-specific preference conservation naturally leads to one plausible evolutionary explanation for the existence of intragenic global suppressor mutations. PMID:25392342

  20. Urinary loss of tricarboxylic acid cycle intermediates as revealed by metabolomics studies: an underlying mechanism to reduce lipid accretion by whey protein ingestion?

    Science.gov (United States)

    Lillefosse, Haldis H; Clausen, Morten R; Yde, Christian C; Ditlev, Ditte B; Zhang, Xumin; Du, Zhen-Yu; Bertram, Hanne C; Madsen, Lise; Kristiansen, Karsten; Liaset, Bjørn

    2014-05-02

    Whey protein intake is associated with the modulation of energy metabolism and altered body composition both in human subjects and in animals, but the underlying mechanisms are not yet elucidated. We fed obesity-prone C57BL/6J mice high-fat diets with either casein (HF casein) or whey (HF whey) for 6 weeks. At equal energy intake and apparent fat and nitrogen digestibility, mice fed HF whey stored less energy as lipids, evident both as lower white adipose tissue mass and as reduced liver lipids, compared with HF-casein-fed mice. Explorative analyses of 48 h urine, both by (1)H NMR and LC-MS metabolomic platforms, demonstrated higher urinary excretion of tricarboxylic acid (TCA) cycle intermediates citric acid and succinic acid (identified by both platforms), and cis-aconitic acid and isocitric acid (identified by LC-MS platform) in the HF whey, relative to in the HF-casein-fed mice. Targeted LC-MS analyses revealed higher citric acid and cis-aconitic acid concentrations in fed state plasma, but not in liver of HF-whey-fed mice. We propose that enhanced urinary loss of TCA cycle metabolites drain available substrates for anabolic processes, such as lipogenesis, thereby leading to reduced lipid accretion in HF-whey-fed compared to HF-casein-fed mice.

  1. Computerbasiert prüfen [Computer-based Assessment

    Directory of Open Access Journals (Sweden)

    Frey, Peter

    2006-08-01

    Full Text Available [english] Computer-based testing in medical education offers new perspectives. Advantages are sequential or adaptive testing, integration of movies or sound, rapid feedback to candidates and management of web-based question banks. Computer-based testing can also be implemented in an OSCE examination. In e-learning environments formative self-assessment are often implemented and gives helpful feedbacks to learners. Disadvantages in high-stake exams are the high requirements as well for the quality of testing (e.g. standard setting as additionally for the information technology and especially for security. [german] Computerbasierte Prüfungen im Medizinstudium eröffnen neue Möglichkeiten. Vorteile solcher Prüfungen liegen im sequentiellen oder adaptiven Prüfen, in der Integration von Bewegtbildern oder Ton, der raschen Auswertung und zentraler Verwaltung der Prüfungsfragen via Internet. Ein Einsatzgebiet mit vertretbarem Aufwand sind Prüfungen mit mehreren Stationen wie beispielsweise die OSCE-Prüfung. Computerbasierte formative Selbsttests werden im Bereiche e-learning häufig angeboten. Das hilft den Lernenden ihren Wissensstand besser einzuschätzen oder sich mit den Leistungen anderer zu vergleichen. Grenzen zeigen sich bei den summativen Prüfungen beim Prüfungsort, da zuhause Betrug möglich ist. Höhere ärztliche Kompetenzen wie Untersuchungstechnik oder Kommunikation eigenen sich kaum für rechnergestützte Prüfungen.

  2. BOREAS TE-1 SSA-Fen Soil Profile Nutrient Data

    Science.gov (United States)

    Papagno, Andrea; Anderson, Darwin; Newcomer, Jeffrey A. (Editor); Hall, Forrest G. (Editor)

    2000-01-01

    The BOREAS TE-1 team collected various data to characterize the soil-plant systems in the BOREAS SSA. Particular emphasis was placed on nutrient biochemistry, the stores and transfers of organic carbon, and how the characteristics were related to measured methane fluxes. The overall traniect in the Prince Albert National Park (Saskatchewan, Canada) included the major plant communities and related soils that occurred in that section of the boreal forest. Soil physical, chemical, and biological measurements along the transect were used to characterize the static environment, which allowed them to be related to methane fluxes. Chamber techniques were used to provide a measure of methane production/uptake. Chamber measurements coupled with flask sampling were used to determine the seasonality of methane fluxes. This particular data set contains soil profile measurements of various nutrients at the SSA-Fen site. The data were collected from 23-May to 21-Oct- 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  3. Targeted metabolomic analysis reveals the association between the postprandial change in palmitic acid, branched-chain amino acids and insulin resistance in young obese subjects.

    Science.gov (United States)

    Liu, Liyan; Feng, Rennan; Guo, Fuchuan; Li, Ying; Jiao, Jundong; Sun, Changhao

    2015-04-01

    Obesity is the result of a positive energy balance and often leads to difficulties in maintaining normal postprandial metabolism. The changes in postprandial metabolites after an oral glucose tolerance test (OGTT) in young obese Chinese men are unclear. In this work, the aim is to investigate the complex metabolic alterations in obesity provoked by an OGTT using targeted metabolomics. We used gas chromatography-mass spectrometry and ultra high performance liquid chromatography-triple quadrupole mass spectrometry to analyze serum fatty acids, amino acids and biogenic amines profiles from 15 control and 15 obese subjects at 0, 30, 60, 90 and 120 min during an OGTT. Metabolite profiles from 30 obese subjects as independent samples were detected in order to validate the change of metabolites. There were the decreased levels of fatty acid, amino acids and biogenic amines after OGTT in obesity. At 120 min, percent change of 20 metabolites in obesity has statistical significance when comparing with the controls. The obese parameters was positively associated with changes in arginine and histidine (Ppalmitic acid (PA), branched-chain amino acids (BCAAs) and phenylalanine between 1 and 120 min were positively associated with fasting insulin and HOMA-IR (all P<0.05) in the obese group. The postprandial metabolite of PA and BCAAs may play important role in the development and onset of insulin resistance in obesity. Our findings offer new insights in the complex physiological regulation of the metabolism during an OGTT in obesity.

  4. Integrated Transcriptome and Metabolic Analyses Reveals Novel Insights into Free Amino Acid Metabolism in Huangjinya Tea Cultivar

    Science.gov (United States)

    Zhang, Qunfeng; Liu, Meiya; Ruan, Jianyun

    2017-01-01

    The chlorotic tea variety Huangjinya, a natural mutant, contains enhanced levels of free amino acids in its leaves, which improves the drinking quality of its brewed tea. Consequently, this chlorotic mutant has a higher economic value than the non-chlorotic varieties. However, the molecular mechanisms behind the increased levels of free amino acids in this mutant are mostly unknown, as are the possible effects of this mutation on the overall metabolome and biosynthetic pathways in tea leaves. To gain further insight into the effects of chlorosis on the global metabolome and biosynthetic pathways in this mutant, Huangjinya plants were grown under normal and reduced sunlight, resulting in chlorotic and non-chlorotic leaves, respectively; their leaves were analyzed using transcriptomics as well as targeted and untargeted metabolomics. Approximately 5,000 genes (8.5% of the total analyzed) and ca. 300 metabolites (14.5% of the total detected) were significantly differentially regulated, thus indicating the occurrence of marked effects of light on the biosynthetic pathways in this mutant plant. Considering primary metabolism, including that of sugars, amino acids, and organic acids, significant changes were observed in the expression of genes involved in both nitrogen (N) and carbon metabolism. The suite of changes not only generated an increase in amino acids, including glutamic acid, glutamine, and theanine, but it also elevated the levels of free ammonium, citrate, and α-ketoglutarate, and lowered the levels of mono- and di-saccharides and of caffeine as compared with the non-chlorotic leaves. Taken together, our results suggest that the increased levels of amino acids in the chlorotic vs. non-chlorotic leaves are likely due to increased protein catabolism and/or decreased glycolysis and diminished biosynthesis of nitrogen-containing compounds other than amino acids, including chlorophyll, purines, nucleotides, and alkaloids.

  5. Identification and characterization of the soybean IPK1 ortholog of a low phytic acid mutant reveals an exon-excluding splice-site mutation.

    Science.gov (United States)

    Yuan, Feng-Jie; Zhu, Dan-Hua; Tan, Yuan-Yuan; Dong, De-Kun; Fu, Xu-Jun; Zhu, Shen-Long; Li, Bai-Quan; Shu, Qing-Yao

    2012-11-01

    Phytic acid (myo-inositol 1, 2, 3, 4, 5, 6 hexakisphosphate) is an important constituent of soybean meal. Since phytic acid and its mineral salts (phytates) are almost indigestible for monogastrics, their abundance in grain food/feed causes nutritional and environmental problems; interest in breeding low phytic acid has therefore increased considerably. Based on gene mapping and the characteristics of inositol polyphosphates profile in the seeds of a soybean mutant line Gm-lpa-ZC-2, the soybean ortholog of inositol 1,3,4,5,6 pentakisphosphate (InsP(5)) 2-kinase (IPK1), which transforms InsP(5) into phytic acid, was first hypothesized as the candidate gene responsible for the low phytic acid alteration in Gm-lpa-ZC-2. One IPK1 ortholog (Glyma14g07880, GmIPK1) was then identified in the mapped region on chromosome 14. Sequencing revealed a G → A point mutation in the genomic DNA sequence and the exclusion of the entire fifth exon in the cDNA sequence of GmIPK1 in Gm-lpa-ZC-2 compared with its wild-type progenitor Zhechun No. 3. The excluded exon encodes 37 amino acids that spread across two conserved IPK1 motifs. Furthermore, complete co-segregation of low phytic acid phenotype with the G → A mutation was observed in the F(2) population of ZC-lpa x Zhexiandou No. 4 (a wild-type cultivar). Put together, the G → A point mutation affected the pre-mRNA splicing and resulted in the exclusion of the fifth exon of GmIPK1 which is expected to disrupt the GmIPK1 functionality, leading to low phytic acid level in Gm-lpa-ZC-2. Gm-lpa-ZC-2, would be a good germplasm source in low phytic acid soybean breeding.

  6. Omics-based approaches reveal phospholipids remodeling of Rhizopus oryzae responding to furfural stress for fumaric acid-production from xylose.

    Science.gov (United States)

    Pan, Xinrong; Liu, Huanhuan; Liu, Jiao; Wang, Cheng; Wen, Jianping

    2016-12-01

    In order to relieve the toxicity of furfural on Rhizopus oryzae fermentation, the molecular mechanism of R. oryzae responding to furfural stress for fumaric acid-production was investigated by omics-based approaches. In metabolomics analysis, 29 metabolites including amino acid, sugars, polyols and fatty acids showed significant changes for maintaining the basic cell metabolism at the cost of lowering fumaric acid production. To further uncover the survival mechanism, lipidomics was carried out, revealing that phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol and polyunsaturated acyl chains might be closely correlated with R. oryzae's adapting to furfural stress. Based on the above omics analysis, lecithin, inositol and soybean oil were exogenously supplemented separately with an optimized concentration in the presence of furfural, which increased fumaric acid titer from 5.78g/L to 10.03g/L, 10.05g/L and 12.13g/L (increased by 73.5%, 73.8% and 110%, respectively). These findings provide a methodological guidance for hemicellulose-fumaric acid development.

  7. Comparisons of soil nitrogen mass balances for an ombrotrophic bog and a minerotrophic fen in northern Minnesota

    Science.gov (United States)

    We compared the N budgets of an ombrotrophic bog and a minerotrophic fen to quantify the importance of denitrification in peatlands and their watersheds. We also compared the watershed upland mineral soils to bog/fen peat; lagg and transition zone peat to central bog/fen peat; an...

  8. Fenómenos complejos en sistemas extendidos en el espacio

    OpenAIRE

    Sánchez de La Lama, Marta

    2009-01-01

    Uno de los aspectos más fascinantes del mundo que nos rodea es la gran variedad de escalas a las que tienen lugar los diversos fenómenos. En muchos casos esta diversidad pone de manifiesto la estructura fractal de la Naturaleza y podemos hablar entonces de fenómenos complejos, en los que eventos de diferentes magnitudes no pueden analizarse de manera independiente. Dicha complejidad emerge como un fenómeno cooperativo a escalas microscópicas, que produce un complejo comportamiento macroscópic...

  9. Fenómenos complejos en sistemas extendidos en el espacio

    OpenAIRE

    Sánchez de La Lama, Marta

    2011-01-01

    RESUMEN: Uno de los aspectos más fascinantes del mundo que nos rodea es la gran variedad de escalas a las que tienen lugar los diversos fenómenos. En muchos casos esta diversidad pone de manifiesto la estructura fractal de la naturaleza y podemos hablar entonces de fenómenos complejos, en los que eventos de diferentes magnitudes no pueden analizarse de manera independiente. Dicha complejidad emerge como un fenómeno cooperativo a escalas microscópicas, que produce un complejo comportamient...

  10. Proteomic analysis of mitochondria reveals a metabolic switch from fatty acid oxidation to glycolysis in the failing heart

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This work characterizes the mitochondrial proteomic profile in the failing heart and elucidates the molecular basis of mitochondria in heart failure. Heart failure was induced in rats by myocardial infarction, and mitochondria were isolated from hearts by differential centrifugation. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight mass spectrometry, a system biology approach was employed to investigate differences in mitochondrial proteins between normal and failing hearts. Mass spectrometry identified 27 proteins differentially expressed that involved in energy metabolism. Among those, the up-regulated proteins included tricarboxylic acid cycle enzymes and pyruvate dehydrogenase complex subunits while the down-regulated proteins were involved in fatty acid oxidation and the OXPHOS complex. These results suggest a substantial metabolic switch from free fatty acid oxidation to glycolysis in heart failure and provide molecular evidence for alterations in the structural and functional parameters of mitochondria that may contribute to cardiac dysfunction during ischemic injury.

  11. Mapping of Saccharomyces cerevisiae metabolites in fermenting wheat straight-dough reveals succinic acid as pH-determining factor.

    Science.gov (United States)

    Jayaram, Vinay B; Cuyvers, Sven; Lagrain, Bert; Verstrepen, Kevin J; Delcour, Jan A; Courtin, Christophe M

    2013-01-15

    Fermenting yeast does not merely cause dough leavening, but also contributes to the bread aroma and might alter dough rheology. Here, the yeast carbon metabolism was mapped during bread straight-dough fermentation. The concentration of most metabolites changed quasi linearly as a function of fermentation time. Ethanol and carbon dioxide concentrations reached up to 60 mmol/100g flour. Interestingly, high levels of glycerol (up to 10 mmol/100g flour) and succinic acid (up to 1.6 mmol/100g flour) were produced during dough fermentation. Further tests showed that, contrary to current belief, the pH decrease in fermenting dough is primarily caused by the production of succinic acid by the yeast instead of carbon dioxide dissolution or bacterial organic acids. Together, our results provide a comprehensive overview of metabolite production during dough fermentation and yield insight into the importance of some of these metabolites for dough properties.

  12. Atributos privativos e musicais do fenômeno noturno

    Directory of Open Access Journals (Sweden)

    Clovis Salgado Gontijo Oliveira Clovis Salgado Gontijo Oliveira

    2015-11-01

    Full Text Available Desde a sua análise como mero fenômeno, elaborada com pretensões de neutralidade, a noite é por nós concebida a partir de atributos predominantemente privativos. Estes se acentuam culturalmente na tradição ocidental, que tende a desvalorizá-los como signos de um vazio de ordem ontológica, epistemológica, ética e, até mesmo, estética. Associadas a uma esfera de negatividade, tais privações parecem impedir ou, pelo menos, dificultar o tratamento artístico da experiência noturna, sobretudo quando este pretende se realizar num modelo de arte em continuidade com uma proposta visual e iluminista. Tomando como base nossa tese de doutorado, intitulada XXX, pretendemos aqui analisar de que modo os atributos privativos referentes à noite não só dificultam a sua mímese quanto estão presentes, sob nova interpretação, em contextos que revalorizam positivamente a experiência noturna, potencializando-a, assim, como motivo. Dentre estes contextos, concederemos particular atenção à arte musical, que, coincidentemente, manifesta para o teórico e o ouvinte alguns dos mesmos atributos privativos identificados na análise primária do noturno. A fim de efetuar este estudo, recorreremos ao pensamento de Vladimir Jankélévitch, principal fundamentação teórica da tese cujo percurso será sintetizado neste artigo.

  13. Factors affecting the interactions between beta-lactoglobulin and fatty acids as revealed in molecular dynamics simulations

    Science.gov (United States)

    Yi, Changhong; Wambo, Thierry O.

    2015-01-01

    Beta-lactoglobulin (BLG), a bovine dairy protein, is a promiscuously interacting protein that can bind multiple hydrophobic ligands. Fatty acids (FAs), common hydrophobic molecules bound to BLG, are important sources of fuel for life because they yield large quantities of ATP when metabolized. The binding affinity increases with the length of the ligands, indicating the importance of the van der Waals (vdW) interactions between the hydrocarbon tail and the hydrophobic calyx of BLG. An exception to this rule is caprylic acid (OCA) which is two-carbon shorter but has a stronger binding affinity than capric acid. Theoretical calculations in the current literature are not accurate enough to shed light on the underlying physics of this exception. The computed affinity values are greater for longer fatty acids without respect for the caprylic exception and those values are generally several orders of magnitude away from the experimental data. In this work, we used hybrid steered molecular dynamics to accurately compute the binding free energies between BLG and the five saturated FAs of 8 to 16 carbon atoms. The computed binding free energies agree well with experimental data not only in rank but also in absolute values. We gained insights into the exceptional behavior of caprylic acid in the computed values of entropy and electrostatic interactions. We found that the electrostatic interaction between the carboxyl group of caprylic acid and the two amino groups of K60/69 in BLG is much stronger than the vdW force between OCA’s hydrophobic tail and the BLG calyx. This pulls OCA to the top of the beta barrel where it is easier to fluctuate, giving rise to greater entropy of OCA at the binding site. PMID:26272099

  14. Los compuestos fenólicos en la autodefensa de los vegetales

    Directory of Open Access Journals (Sweden)

    Maestro-Durán, R.

    1993-12-01

    Full Text Available This article covers the studies on phytoalexins activity of phenolic compounds (cinnamic acids, flavonoids, isoflavonoids, deoxianthocyanins, stilbenes, coumarins, chromones against fungi and bacteria. The relationship between hydrophilic-lipophilic balance activity is reported. Finally some reports on the preparation of synthetic phytoalexins sharing structural similarities with the natural ones (stilbenes, epi-catechin derivatives, of commercial interest as pesticides, insecticides and fungicides, are revised.

    En este trabajo se recogen los estudios sobre la actividad como fitoalexinas (compuestos post-infeccionales cuya formación implica o desrrepresión de genes o activación de un sistema enzimático que no operaba antes de la infección, tanto frente a hongos como frente a bacterias, de compuestos de tipo fenólico (ácidos cinámicos, flavonoides, isoflavonoides, deoxiantocianinas, estilbenos, cumarinas, cromonas. Se señala la relación entre el balance hidrófilo-lipófilo y la actividad como fitoalexinas. Finalmente se recogen trabajos sobre la obtención de fitoalexinas sintéticas de estructuras similares a las naturales (estilbenos, derivados de epicatequinas de interés comercial como pesticidas, insecticidas o fungicidas.

  15. Fatty acids and small organic compounds bind to mineralo-organic nanoparticles derived from human body fluids as revealed by metabolomic analysis.

    Science.gov (United States)

    Martel, Jan; Wu, Cheng-Yeu; Hung, Cheng-Yu; Wong, Tsui-Yin; Cheng, Ann-Joy; Cheng, Mei-Ling; Shiao, Ming-Shi; Young, John D

    2016-03-14

    Nanoparticles entering the human body instantly become coated with a "protein corona" that influences the effects and distribution of the particles in vivo. Yet, whether nanoparticles may bind to other organic compounds remains unclear. Here we use an untargeted metabolomic approach based on ultra-performance liquid chromatography and quadruple time-of-flight mass spectrometry to identify the organic compounds that bind to mineral nanoparticles formed in human body fluids (serum, plasma, saliva, and urine). A wide range of organic compounds is identified, including fatty acids, glycerophospholipids, amino acids, sugars, and amides. Our results reveal that, in addition to the proteins identified previously, nanoparticles harbor an "organic corona" containing several fatty acids which may affect particle-cell interactions in vivo. This study provides a platform to study the organic corona of biological and synthetic nanoparticles found in the human body.

  16. Metabolism of Seriola lalandi during Starvation as Revealed by Fatty Acid Analysis and Compound-Specific Analysis of Stable Isotopes within Amino Acids

    Science.gov (United States)

    Barreto-Curiel, Fernando; Focken, Ulfert; D’Abramo, Louis R.

    2017-01-01

    Fish starvation is defined as food deprivation for a long period of time, such that physiological processes become confined to basal metabolism. Starvation provides insights in physiological processes without interference from unknown factors in digestion and nutrient absorption occurring in fed state. Juveniles of amberjack Seriola lalandi were isotopically equilibrated to a formulated diet for 60 days. One treatment consisted of fish that continued to be fed and fish in the other treatment were not fed for 35 days. The isotopic signatures prior to the beginning of and after the starvation period, for fish in the starvation and control treatments, were analysed for lipid content, fatty acid composition and isotopic analysis of bulk (EA-IRMS) and of amino acids (compound specific isotope analysis, CSIA). There were three replicates for the starvation group. Fatty acid content in muscle and liver tissue before and after starvation was determined to calculate percent change. Results showed that crude lipid was the most used source of energy in most cases; the PUFAs and LC-PUFAs were highly conserved. According to the protein signature in bulk (δ15N) and per amino acid (δ13C and δ15N), in muscle tissue, protein synthesis did not appear to occur substantially during starvation, whereas in liver, increases in δ13C and δ15N indicate that protein turnover occurred, probably for metabolic routing to energy-yielding processes. As a result, isotopic values of δ15N in muscle tissue do not change, whereas CSIA net change occurred in the liver tissue. During the study period of 35 days, muscle protein was largely conserved, being neither replenished from amino acid pools in the plasma and liver nor catabolized. PMID:28095488

  17. Response of anaerobic carbon cycling to water table manipulation in an Alaskan rich fen

    Science.gov (United States)

    Kane, E.S.; Chivers, M.R.; Turetsky, M.R.; Treat, C.C.; Petersen, D.G.; Waldrop, M.; Harden, J.W.; McGuire, A.D.

    2013-01-01

    To test the effects of altered hydrology on organic soil decomposition, we investigated CO2 and CH4 production potential of rich-fen peat (mean surface pH = 6.3) collected from a field water table manipulation experiment including control, raised and lowered water table treatments. Mean anaerobic CO2 production potential at 10 cm depth (14.1 ± 0.9 μmol C g−1 d−1) was as high as aerobic CO2 production potential (10.6 ± 1.5 μmol C g−1 d−1), while CH4 production was low (mean of 7.8 ± 1.5 nmol C g−1 d−1). Denitrification enzyme activity indicated a very high denitrification potential (197 ± 23 μg N g−1 d−1), but net NO-3 reduction suggested this was a relatively minor pathway for anaerobic CO2 production. Abundances of denitrifier genes (nirK and nosZ) did not change across water table treatments. SO2-4 reduction also did not appear to be an important pathway for anaerobic CO2 production. The net accumulation of acetate and formate as decomposition end products in the raised water table treatment suggested that fermentation was a significant pathway for carbon mineralization, even in the presence of NO-3. Dissolved organic carbon (DOC) concentrations were the strongest predictors of potential anaerobic and aerobic CO2 production. Across all water table treatments, the CO2:CH4 ratio increased with initial DOC leachate concentrations. While the field water table treatment did not have a significant effect on mean CO2 or CH4 production potential, the CO2:CH4 ratio was highest in shallow peat incubations from the drained treatment. These data suggest that with continued drying or with a more variable water table, anaerobic CO2 production may be favored over CH4 production in this rich fen. Future research examining the potential for dissolved organic substances to facilitate anaerobic respiration, or alternative redox processes that limit the effectiveness of organic acids as substrates in anaerobic metabolism, would help explain additional

  18. Screening of lactic acid bacteria from Indonesia reveals glucansucrase and fructansucrase genes in two different Weissella confusa strains from soya

    NARCIS (Netherlands)

    Malik, Amarila; Radji, Maksum; Kralj, Slavko; Dijkhuizen, Lubbert

    2009-01-01

    Homopolysaccharide (glucan and fructan) synthesis from sucrose by sucrase enzymes in lactic acid bacteria (LAB) has been well studied in the genera Leuconostoc, Streptococcus and Lactobacillus. This study aimed to identify and characterize genes encoding glucansucrase/glucosyltransferase (GTF) and f

  19. Greenhouse gas emissions from fen soils used for forage production in northern Germany

    Science.gov (United States)

    Poyda, Arne; Reinsch, Thorsten; Kluß, Christof; Loges, Ralf; Taube, Friedhelm

    2016-09-01

    A large share of peatlands in northwestern Germany is drained for agricultural purposes, thereby emitting high amounts of greenhouse gases (GHGs). In order to quantify the climatic impact of fen soils in dairy farming systems of northern Germany, GHG exchange and forage yield were determined on four experimental sites which differed in terms of management and drainage intensity: (a) rewetted and unutilized grassland (UG), (b) intensive and wet grassland (GW), (c) intensive and moist grassland (GM) and (d) arable forage cropping (AR). Net ecosystem exchange (NEE) of CO2 and fluxes of CH4 and N2O were measured using closed manual chambers. CH4 fluxes were significantly affected by groundwater level (GWL) and soil temperature, whereas N2O fluxes showed a significant relation to the amount of nitrate in top soil. Annual balances of all three gases, as well as the global warming potential (GWP), were significantly correlated to mean annual GWL. A 2-year mean GWP, combined from CO2-C eq. of NEE, CH4 and N2O emissions, as well as C input (slurry) and C output (harvest), was 3.8, 11.7, 17.7 and 17.3 Mg CO2-C eq. ha-1 a-1 for sites UG, GW, GM and AR, respectively (standard error (SE) 2.8, 1.2, 1.8, 2.6). Yield-related emissions for the three agricultural sites were 201, 248 and 269 kg CO2-C eq. (GJ net energy lactation; NEL)-1 for sites GW, GM and AR, respectively (SE 17, 9, 19). The carbon footprint of agricultural commodities grown on fen soils depended on long-term drainage intensity rather than type of management, but management and climate strongly influenced interannual on-site variability. However, arable forage production revealed a high uncertainty of yield and therefore was an unsuitable land use option. Lowest yield-related GHG emissions were achieved by a three-cut system of productive grassland swards in combination with a high GWL (long-term mean ≤ 20 cm below the surface).

  20. Effects of Perfluorooctanoic Acid on Metabolic Profiles in Brain and Liver of Mouse Revealed by a High-throughput Targeted Metabolomics Approach

    Science.gov (United States)

    Yu, Nanyang; Wei, Si; Li, Meiying; Yang, Jingping; Li, Kan; Jin, Ling; Xie, Yuwei; Giesy, John P.; Zhang, Xiaowei; Yu, Hongxia

    2016-04-01

    Perfluorooctanoic acid (PFOA), a perfluoroalkyl acid, can result in hepatotoxicity and neurobehavioral effects in animals. The metabolome, which serves as a connection among transcriptome, proteome and toxic effects, provides pathway-based insights into effects of PFOA. Since understanding of changes in the metabolic profile during hepatotoxicity and neurotoxicity were still incomplete, a high-throughput targeted metabolomics approach (278 metabolites) was used to investigate effects of exposure to PFOA for 28 d on brain and liver of male Balb/c mice. Results of multivariate statistical analysis indicated that PFOA caused alterations in metabolic pathways in exposed individuals. Pathway analysis suggested that PFOA affected metabolism of amino acids, lipids, carbohydrates and energetics. Ten and 18 metabolites were identified as potential unique biomarkers of exposure to PFOA in brain and liver, respectively. In brain, PFOA affected concentrations of neurotransmitters, including serotonin, dopamine, norepinephrine, and glutamate in brain, which provides novel insights into mechanisms of PFOA-induced neurobehavioral effects. In liver, profiles of lipids revealed involvement of β-oxidation and biosynthesis of saturated and unsaturated fatty acids in PFOA-induced hepatotoxicity, while alterations in metabolism of arachidonic acid suggesting potential of PFOA to cause inflammation response in liver. These results provide insight into the mechanism and biomarkers for PFOA-induced effects.

  1. Differences in potential for amino acid change after mutation reveals distinct strategies for kappa and lambda light-chain variation.

    Science.gov (United States)

    Hershberg, Uri; Shlomchik, Mark J

    2006-10-24

    B cells generate varied yet functional clones under high rates of mutation of their V genes. It has been proposed that as a result of the opposing demands of diversification and preservation of integrity, the V genes of heavy and light chains have evolved to overexpress codons prone to amino acid change in their complementarity determining regions (CDR) compared with the framework (FW) regions. We have analyzed the germ-line V genes of heavy and light chains (both kappa and lambda), comparing codons of CDR and FW of the germ-line V regions both to each other and to control regions. We found that in both germ-line heavy chains and lambda chains, CDR codons are prone to replacement mutations, whereas in the FW, the opposite is true. Furthermore, the difference between CDR and FW in heavy chains and lambda chains is based on codons that are prone to nonconservative changes of amino acid. In contrast, in germ-line kappa chains, the codons in both CDR and FW are more prone to replacement mutations. We also demonstrated that negative selection during immune responses is more sensitive to nonconservative amino acid substitutions than overall amino acid change, demonstrating the applicability of our analysis to real-time process of selection in the immune system. The differences in germ-line kappa and lambda light chains' potential reaction to mutation suggests that via these two differently evolved light-chain types, the B cell repertoire encompasses two different strategies to balance diversity and stability in an immune response.

  2. Novel and Unexpected Microbial Diversity in Acid Mine Drainage in Svalbard (78° N), Revealed by Culture-Independent Approaches

    OpenAIRE

    Antonio García-Moyano; Andreas Erling Austnes; Anders Lanzén; Elena González-Toril; Ángeles Aguilera; Lise Øvreås

    2015-01-01

    Svalbard, situated in the high Arctic, is an important past and present coal mining area. Dozens of abandoned waste rock piles can be found in the proximity of Longyearbyen. This environment offers a unique opportunity for studying the biological control over the weathering of sulphide rocks at low temperatures. Although the extension and impact of acid mine drainage (AMD) in this area is known, the native microbial communities involved in this process are still scarcely studied and uncharact...

  3. IRMPD spectroscopy reveals a novel rearrangement reaction for modified peptides that involves elimination of the N-terminal amino acid

    NARCIS (Netherlands)

    van Stipdonk, M.J.; Patterson, K.; Gibson, J.K.; Berden, G.; Oomens, J.

    2015-01-01

    In this study, peptides were derivatized by reaction with salicylaldehyde to create N-terminal imines (Schiff bases). Collision-induced dissociation of the imine-modified peptides produces a complete series of b and a ions (which reveal sequence). However, an unusual pathway is also observed, one th

  4. Proteomic analysis of mitochondria reveals a metabolic switch from fatty acid oxidation to glycolysis in the failing heart

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; WANG TingZhong; LIU Ping; FAN FenLing; GUAN YouFei; MA AiQun; BAI Ling; LI Jing; SUN ChaoFeng; ZHAO Jin; CUI ChangCong; HAN Ke; LIU Yu; ZHUO XiaoZhen

    2009-01-01

    This work characterizes the mitochondrial proteomic profile in the failing heart and elucidates the molecular basis of mitochondria in heart failure.Heart failure was induced in rats by myocardial infarction,and mitochondria were isolated from hearts by differential centrifugation.Using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight mass spectrometry,a system biology approach was employed to investigate differences in mitochondrial proteins between normal and failing hearts.Mass spectrometry identified 27 proteins differentially expressed that involved in energy metabolism.Among those,the up-regulated proteins included tricarboxylic acid cycle enzymes and pyruvate dehydrogenase complex subunita while the down-regulated proteins were involved in fatty acid oxidation and the OXPHOS complex.These results suggest a substantial metabolic switch from free fatty acid oxidation to glycolysis in heart failure and provide molecular evidence for alterations in the structural and functional parameters of mitochondria that may contribute to cardiac dysfunction during ischemic injury.

  5. Mass Spectrometry Analysis Coupled with de novo Sequencing Reveals Amino Acid Substitutions in Nucleocapsid Protein from Influenza A Virus

    Directory of Open Access Journals (Sweden)

    Zijian Li

    2014-02-01

    Full Text Available Amino acid substitutions in influenza A virus are the main reasons for both antigenic shift and virulence change, which result from non-synonymous mutations in the viral genome. Nucleocapsid protein (NP, one of the major structural proteins of influenza virus, is responsible for regulation of viral RNA synthesis and replication. In this report we used LC-MS/MS to analyze tryptic digestion of nucleocapsid protein of influenza virus (A/Puerto Rico/8/1934 H1N1, which was isolated and purified by SDS poly-acrylamide gel electrophoresis. Thus, LC-MS/MS analyses, coupled with manual de novo sequencing, allowed the determination of three substituted amino acid residues R452K, T423A and N430T in two tryptic peptides. The obtained results provided experimental evidence that amino acid substitutions resulted from non-synonymous gene mutations could be directly characterized by mass spectrometry in proteins of RNA viruses such as influenza A virus.

  6. Fenômeno de Raynaud Raynaud's phenomenon

    Directory of Open Access Journals (Sweden)

    Cristiane Kayser

    2009-02-01

    Full Text Available O fenômeno de Raynaud (FRy caracteriza-se por episódios reversíveis de vasoespasmos de extremidades, associados a palidez, seguido por cianose e rubor de mãos e pés, que ocorrem usualmente após estresse ou exposição ao frio. O FRy primário é um evento funcional benigno e não está associado a nenhuma doença ou condição subjacente. Já o FRy secundário pode estar associado a uma série de condições, principalmente a doenças reumáticas autoimunes. Na esclerose sistêmica (ES, o FRy é a manifestação inicial mais frequente. No FRy secundário às doenças do espectro da ES, complicações como lesões isquêmicas de extremidades são frequentes. Nos últimos anos, avanços no estudo da fisiopatologia do FRy e da doença vascular na ES propiciaram o surgimento de opções terapêuticas bastante promissoras para essa manifestação. Nesta revisão pretendemos discorrer principalmente sobre a patogênese, a investigação clínica e o tratamento do FRy, com ênfase nos novos tratamentos disponíveis.Raynaud's phenomenon (RP is an episodic vasospasm of the peripheral arterioles, causing pallor followed by cyanosis and redness of the fingers and toes, usually in response to stress or cold exposure. Primary Raynaud's phenomenon is a benign event and occurs without an underlying disease. In contrast, secondary Raynaud's phenomenon can occur in association with several underlying diseases or conditions, mostly autoimmune rheumatic diseases. In systemic sclerosis (SSc, RP is the most frequent initial manifestation. In RP secondary to SSc-related diseases, digital ischemic lesions are a frequent problem. In recent years, advances in the understanding of the physiopathology of RP have favored the development of novel promising therapeutic alternatives for this clinical condition. This article presents a review of the pathogenesis, clinical investigation and treatment of RP, with special emphasis in novel therapeutic modalities.

  7. Fenómeno de Raynaud Raynaud's Phenomenon

    Directory of Open Access Journals (Sweden)

    Ivone Silva

    2011-03-01

    Full Text Available O Fenómeno de Raynaud (FR é uma manifestação clínica comum, traduzida por vasoespasmos recorrentes dos dedos, na maioria das vezes provocados pela exposição ao frio ou estímulos emocionais. Pode ser primário (idiopática ou secundária a diversas doenças ou condições, incluindo doenças do tecido conjuntivo, como esclerose sistémica. A patogênese da FR é mal compreendido. Actualmente pensa-se que a lesão endotelial e a disfunção vascular associada podem ser as primeiras alteração patogénicas e responsável pelas complicações vasculares nos doentes com RP. As alterações funcionais (vasoconstrição e as mudanças estruturais (proliferação intimal e obstrução dos capilares e artérias, traduzem-se clinicamente como RP e úlceras digitais. O FR é em muitos casos a primeira manifestação da doença secundária associado e precede as outras manifestações clínicas em anos.Raynaud´s Phenomenon (RP is a common clinical disorder, manifested by recurrent vasospasm of fingers and toes, often triggered by exposure to cold temperatures or emotional stress. It can be primary (idiopathic or secondary to several diseases or conditions, including connective tissue diseases such as systemic sclerosis. The pathogenesis of RP is poorly understood. It is generally accepted that endothelial damage and vascular dysfunction may be the earliest pathogenetic alteration and ethological factor responsible for vascular complications in RP patients. Functional abnormalities (vasoconstriction and structural changes (intimal proliferation, obstruction are expressed clinically as RP and digital ulcers. RP is the first manifestation of the secondary associated disease and precedes other clinical manifestations by years.

  8. Volatile profiling reveals intracellular metabolic changes in Aspergillus parasiticus: veA regulates branched chain amino acid and ethanol metabolism

    Directory of Open Access Journals (Sweden)

    Roze Ludmila V

    2010-08-01

    Full Text Available Abstract Background Filamentous fungi in the genus Aspergillus produce a variety of natural products, including aflatoxin, the most potent naturally occurring carcinogen known. Aflatoxin biosynthesis, one of the most highly characterized secondary metabolic pathways, offers a model system to study secondary metabolism in eukaryotes. To control or customize biosynthesis of natural products we must understand how secondary metabolism integrates into the overall cellular metabolic network. By applying a metabolomics approach we analyzed volatile compounds synthesized by Aspergillus parasiticus in an attempt to define the association of secondary metabolism with other metabolic and cellular processes. Results Volatile compounds were examined using solid phase microextraction - gas chromatography/mass spectrometry. In the wild type strain Aspergillus parasiticus SU-1, the largest group of volatiles included compounds derived from catabolism of branched chain amino acids (leucine, isoleucine, and valine; we also identified alcohols, esters, aldehydes, and lipid-derived volatiles. The number and quantity of the volatiles produced depended on media composition, time of incubation, and light-dark status. A block in aflatoxin biosynthesis or disruption of the global regulator veA affected the volatile profile. In addition to its multiple functions in secondary metabolism and development, VeA negatively regulated catabolism of branched chain amino acids and synthesis of ethanol at the transcriptional level thus playing a role in controlling carbon flow within the cell. Finally, we demonstrated that volatiles generated by a veA disruption mutant are part of the complex regulatory machinery that mediates the effects of VeA on asexual conidiation and sclerotia formation. Conclusions 1 Volatile profiling provides a rapid, effective, and powerful approach to identify changes in intracellular metabolic networks in filamentous fungi. 2 VeA coordinates the

  9. Volatile profiling reveals intracellular metabolic changes in Aspergillus parasiticus: veA regulates branched chain amino acid and ethanol metabolism

    Science.gov (United States)

    2010-01-01

    Background Filamentous fungi in the genus Aspergillus produce a variety of natural products, including aflatoxin, the most potent naturally occurring carcinogen known. Aflatoxin biosynthesis, one of the most highly characterized secondary metabolic pathways, offers a model system to study secondary metabolism in eukaryotes. To control or customize biosynthesis of natural products we must understand how secondary metabolism integrates into the overall cellular metabolic network. By applying a metabolomics approach we analyzed volatile compounds synthesized by Aspergillus parasiticus in an attempt to define the association of secondary metabolism with other metabolic and cellular processes. Results Volatile compounds were examined using solid phase microextraction - gas chromatography/mass spectrometry. In the wild type strain Aspergillus parasiticus SU-1, the largest group of volatiles included compounds derived from catabolism of branched chain amino acids (leucine, isoleucine, and valine); we also identified alcohols, esters, aldehydes, and lipid-derived volatiles. The number and quantity of the volatiles produced depended on media composition, time of incubation, and light-dark status. A block in aflatoxin biosynthesis or disruption of the global regulator veA affected the volatile profile. In addition to its multiple functions in secondary metabolism and development, VeA negatively regulated catabolism of branched chain amino acids and synthesis of ethanol at the transcriptional level thus playing a role in controlling carbon flow within the cell. Finally, we demonstrated that volatiles generated by a veA disruption mutant are part of the complex regulatory machinery that mediates the effects of VeA on asexual conidiation and sclerotia formation. Conclusions 1) Volatile profiling provides a rapid, effective, and powerful approach to identify changes in intracellular metabolic networks in filamentous fungi. 2) VeA coordinates the biosynthesis of secondary

  10. Novel wetland reclamation design : the Suncor Pilot Fen and Wapisiw Wetland

    Energy Technology Data Exchange (ETDEWEB)

    Daly, C. [Suncor Energy Inc., Calgary, AB (Canada); Atkinson, J.; McKenna, G.; Russell, B. [BGC Engineering, Calgary, AB (Canada); Birkham, T.; Chapman, D.; O' Kane, M. [O' Kane Consultants Inc., Saskatoon, SK (Canada); Ciborowski, J. [Windsor Univ., ON (Canada); Price, J. [Waterloo Univ., ON (Canada); Rochefort, L. [Laval Univ., Quebec City, PQ (Canada)

    2010-07-01

    This study evaluated the reclamation of a mined landscape to recreate a fen and its watershed on the Suncor land lease using tailings. Wetlands covered about half of Suncor's lease prior to disturbance by oil sands mining. The purpose of this study was to create a self-sustaining physical environment that is carbon-accumulating, capable of supporting a representative assemblage of species and resilient to normal periodic stresses. The study offers a better understanding of design implications and contributes to the development of optimal designs and protocols. Since the 1980s, much effort has focused on recreating wetland ecosystems, mainly marshes on the reclaimed landscape. However, there has been little effort in recreating a fen ecosystems until recently. The Suncor Pilot Fen will be among the first constructed in the world. Fens support a variety of aquatic plant communities and wildlife and have large carbon and water storage capacities. This Pilot Fen program will determine which fen plant species are tolerant to tailings and saline conditions. It will include site investigation, design, construction and monitoring. This presentation also reviewed the Wapisiw Wetland Program, which will evaluate whether new habitat features will increase floral and faunal diversity and abundance in a newly constructed marsh built on a former tailings pond, Wapisiw Lookout, the first reclaimed oil sands tailings pond. This presentation provided an overview of both these innovative wetland reclamation programs that will help shape future reclamation efforts of Suncor and other oil sands producers.

  11. Surface properties and intracellular speciation revealed an original adaptive mechanism to arsenic in the acid mine drainage bio-indicator Euglena mutabilis.

    Science.gov (United States)

    Halter, David; Casiot, Corinne; Heipieper, Hermann J; Plewniak, Frédéric; Marchal, Marie; Simon, Stéphane; Arsène-Ploetze, Florence; Bertin, Philippe N

    2012-02-01

    Euglena mutabilis is a protist ubiquitously found in extreme environments such as acid mine drainages which are often rich in arsenic. The response of E. mutabilis to this metalloid was compared to that of Euglena gracilis, a protist not found in such environments. Membrane fatty acid composition, cell surface properties, arsenic accumulation kinetics, and intracellular arsenic speciation were determined. The results revealed a modification in fatty acid composition leading to an increased membrane fluidity in both Euglena species under sublethal arsenic concentrations exposure. This increased membrane fluidity correlated to an induced gliding motility observed in E. mutabilis in the presence of this metalloid but did not affect the flagellar dependent motility of E. gracilis. Moreover, when compared to E. gracilis, E. mutabilis showed highly hydrophobic cell surface properties and a higher tolerance to water-soluble arsenical compounds but not to hydrophobic ones. Finally, E. mutabilis showed a lower accumulation of total arsenic in the intracellular compartment and an absence of arsenic methylated species in contrast to E. gracilis. Taken together, our results revealed the existence of a specific arsenical response of E. mutabilis that may play a role in its hypertolerance to this toxic metalloid.

  12. Pyrosequencing reveals the key microorganisms involved in sludge alkaline fermentation for efficient short-chain fatty acids production.

    Science.gov (United States)

    Zheng, Xiong; Su, Yinglong; Li, Xiang; Xiao, Naidong; Wang, Dongbo; Chen, Yinguang

    2013-05-07

    Short-chain fatty acids (SCFAs) have been regarded as the excellent carbon source of wastewater biological nutrient removal, and sludge alkaline (pH 10) fermentation has been reported to achieve highly efficient SCFAs production. In this study, the underlying mechanisms for the improved SCFAs production at pH 10 were investigated by using 454 pyrosequencing and fluorescent in situ hybridization (FISH) to analyze the microbial community structures in sludge fermentation reactors. It was found that sludge fermentation at pH 10 increased the abundances of Pseudomonas sp. and Alcaligenes sp., which were able to excrete extracellular proteases and depolymerases, and thus enhanced the hydrolysis of insoluble sludge protein and polyhydroxyalkanoates (PHA). Meanwhile, the abundance of acid-producing bacteria (such as Clostridium sp.) in the reactor of pH 10 was also higher than that of uncontrolled pH, which benefited the acidification of soluble organic substrates. Further study indicated that sludge fermentation at pH 10 significantly decreased the number of methanogenic archaea, resulting in lower SCFAs consumption and lower methane production. Therefore, anaerobic sludge fermentation under alkaline conditions increased the abundances of bacteria involved in sludge hydrolysis and acidification, and decreased the abundance of methanogenic archaea, which favored the competition of bacteria over methanogens and resulted in the efficient production of SCFAs.

  13. New insights into the diets of harbor seals in the Salish Sea revealed by quantitative fatty acid signature analysis

    Science.gov (United States)

    Bromaghin, Jeffrey F.; Lance, Monique M.; Elliott, Elizabeth W.; Jeffries, Steven J.; Acevedo-Gutiérrez, Alejandro; Kennish, John M.

    2012-01-01

    Harbor seals (Phoca vitulina) are an abundant predator along the west coast of North America, and there is considerable interest in their diet composition, especially in regard to predation on valued fish stocks. Available information on harbor seal diets, primarily derived from scat analysis, suggests that adult salmon (Oncorhynchus spp.), Pacific Herring (Clupea pallasii), and gadids predominate. Because diet assessments based on scat analysis may be biased, we investigated diet composition through quantitative analysis of fatty acid signatures. Blubber samples from 49 harbor seals captured in western North America from haul-outs within the area of the San Juan Islands and southern Strait of Georgia in the Salish Sea were analyzed for fatty acid composition, along with 269 fish and squid specimens representing 27 potential prey classes. Diet estimates varied spatially, demographically, and among individual harbor seals. Findings confirmed the prevalence of previously identified prey species in harbor seal diets, but other species also contributed significantly. In particular, Black (Sebastes melanops) and Yellowtail (S. flavidus) Rockfish were estimated to compose up to 50% of some individual seal diets. Specialization and high predation rates on Black and Yellowtail Rockfish by a subset of harbor seals may play a role in the population dynamics of these regional rockfish stocks that is greater than previously realized.

  14. Viscosities of FenO-MgO-SiO2 and FenO-MgO-CaO-SiO2 slags

    Institute of Scientific and Technical Information of China (English)

    戴曦; 甘雪萍; 张传福

    2003-01-01

    The viscosities of molten Fen O-MgO-SiO2 and Fen O-MgO-CaO-SiO2 semi-synthetic slags for nickel flash smelting were mearured in the temperature range of 1 200-1 450℃ by use of a rotational viscometer.The mass ratio of Fe to SiO2 was fixed at 1.2,calcium oxide and magnesium oxide contents varied in the range of 2%-8% and 9%-12%(mass fraction),respectively.The results show that silicate anions become smaller by increasing CaO content,which results in the viscosity decrease of slag.In the case of addition of MgO the viscosity behaviour is complicated When MgO content is less than 11%,the viscosity increases with the increase of MgO at all temperatures tested .However,when the MgO content is more than 11%,the viscosity decreases slightly for Fen O-MgO-CaOSiO2 system.At higher MgO contents,low-viscosity slags can be obtained by adding CaO.As for a given composition,the viscosity decreased with increasing temperature.The higher the temperature,the more MgO can be added before saturation.The effect of Fe3 O4 on the viscosity is quite significant.The viscosity of slag increases to 300 mpa tions of temperature and composition.A comparison between Fen O-MgO-SiO2 and Fen O-MgO-CaO-SiO2 systems are also given.

  15. Investigation of a 6-MSA Synthase Gene Cluster in Aspergillus aculeatus Reveals 6-MSA-derived Aculinic Acid, Aculins A-B and Epi-Aculin A.

    Science.gov (United States)

    Petersen, Lene M; Holm, Dorte K; Gotfredsen, Charlotte H; Mortensen, Uffe H; Larsen, Thomas O

    2015-10-12

    Aspergillus aculeatus, a filamentous fungus belonging to the Aspergillus clade Nigri, is an industrial workhorse in enzyme production. Recently we reported a number of secondary metabolites from this fungus; however, its genetic potential for the production of secondary metabolites is vast. In this study we identified a 6-methylsalicylic acid (6-MSA) synthase from A. aculeatus, and verified its functionality by episomal expression in A. aculeatus and heterologous expression in A. nidulans. Feeding studies with fully (13) C-labeled 6-MSA revealed that 6-MSA is incorporated into aculinic acid, which further incorporates into three compounds that we name aculins A and B, and epi-aculin A, described here for the first time. Based on NMR data and bioinformatic studies we propose the structures of the compounds as well as a biosynthetic pathway leading to formation of aculins from 6-MSA.

  16. Yeast and bacterial diversity along a transect in an acidic, As-Fe rich environment revealed by cultural approaches.

    Science.gov (United States)

    Delavat, François; Lett, Marie-Claire; Lièvremont, Didier

    2013-10-01

    Acid mine drainages (AMDs) are often thought to harbour low biodiversity, yet little is known about the diversity distribution along the drainages. Using culture-dependent approaches, the microbial diversity from the Carnoulès AMD sediment was investigated for the first time along a transect showing progressive environmental stringency decrease. In total, 20 bacterial genera were detected, highlighting a higher bacterial diversity than previously thought. Moreover, this approach led to the discovery of 16 yeast species, demonstrating for the first time the presence of this important phylogenetic group in this AMD. All in all, the location of the microbes along the transect helps to better understand their distribution in a pollution gradient.

  17. Targeting melanoma growth and viability reveals dualistic functionality of the phosphonothionate analogue of carba cyclic phosphatidic acid

    Directory of Open Access Journals (Sweden)

    Prestwich Glenn D

    2010-06-01

    Full Text Available Abstract Background Although the incidence of melanoma in the U.S. is rising faster than any other cancer, the FDA-approved chemotherapies lack efficacy for advanced disease, which results in poor overall survival. Lysophosphatidic acid (LPA, autotaxin (ATX, the enzyme that produces LPA, and the LPA receptors represent an emerging group of therapeutic targets in cancer, although it is not known which of these is most effective. Results Herein we demonstrate that thio-ccPA 18:1, a stabilized phosphonothionate analogue of carba cyclic phosphatidic acid, ATX inhibitor and LPA1/3 receptor antagonist, induced a marked reduction in the viability of B16F10 metastatic melanoma cells compared with PBS-treated control by 80-100%. Exogenous LPA 18:1 or D-sn-1-O-oleoyl-2-O-methylglyceryl-3-phosphothioate did not reverse the effect of thio-ccPA 18:1. The reduction in viability mediated by thio-ccPA 18:1 was also observed in A375 and MeWo melanoma cell lines, suggesting that the effects are generalizable. Interestingly, siRNA to LPA3 (siLPA3 but not other LPA receptors recapitulated the effects of thio-ccPA 18:1 on viability, suggesting that inhibition of the LPA3 receptor is an important dualistic function of the compound. In addition, siLPA3 reduced proliferation, plasma membrane integrity and altered morphology of A375 cells. Another experimental compound designed to antagonize the LPA1/3 receptors significantly reduced viability in MeWo cells, which predominantly express the LPA3 receptor. Conclusions Thus the ability of thio-ccPA 18:1 to inhibit the LPA3 receptor and ATX are key to its molecular mechanism, particularly in melanoma cells that predominantly express the LPA3 receptor. These observations necessitate further exploration and exploitation of these targets in melanoma.

  18. Dissociative Ionization Mechanism and Appearance Energies in Adipic Acid Revealed by Imaging Photoelectron Photoion Coincidence, Selective Deuteration, and Calculations.

    Science.gov (United States)

    Heringa, Maarten F; Slowik, Jay G; Prévôt, André S H; Baltensperger, Urs; Hemberger, Patrick; Bodi, Andras

    2016-05-26

    Adipic acid, a model compound for oxygenated organic aerosol, has been studied at the VUV beamline of the Swiss Light Source. Internal energy selected cations were prepared by threshold photoionization using vacuum ultraviolet synchrotron radiation and imaging photoelectron photoion coincidence spectroscopy (iPEPICO). The threshold photoelectron spectrum yields a vertical ionization energy (IE) of 10.5 eV, significantly above the calculated adiabatic IE of 8.6 eV. The cationic minimum is accessible after vertical ionization by H-transfer from one of the γ-carbons to a carbonyl oxygen and is sufficiently energetic to decay by water loss at the ionization onset. The slope of the breakdown curves, quantum chemical calculations, and selective deuteration of the carboxylic hydrogens establish the dissociative photoionization mechanism. After ionization, one γ-methylene hydrogen and the two carboxylic hydrogens are randomized prior to H2O loss. On the basis of the deuteration degree in the H2O + CO-loss product at higher energies, a direct water-loss channel without complete randomization also exists. The breakdown diagram and center of gravity of the H2O + CO-loss peak were modeled to obtain 0 K appearance energies of 10.77, 10.32, and 11.53 eV for H2O + CO loss, CH2COOH loss, and H2O + CH2COOH loss from adipic acid. These agree well with the CBS-QB3 calculated values of 10.68, 10.45, and 11.57 eV, respectively, which shows that threshold photoionization can yield energetics data as long as the dissociation is statistical, even when the parent ion cannot be observed. The results can be used as a starting point for a deeper understanding of the ionization and low-energy fragmentation of organic aerosol components.

  19. Silencing of ABCC13 transporter in wheat reveals its involvement in grain development, phytic acid accumulation and lateral root formation.

    Science.gov (United States)

    Bhati, Kaushal Kumar; Alok, Anshu; Kumar, Anil; Kaur, Jagdeep; Tiwari, Siddharth; Pandey, Ajay Kumar

    2016-07-01

    Low phytic acid is a trait desired in cereal crops and can be achieved by manipulating the genes involved either in its biosynthesis or its transport in the vacuoles. Previously, we have demonstrated that the wheat TaABCC13 protein is a functional transporter, primarily involved in heavy metal tolerance, and a probable candidate gene to achieve low phytate wheat. In the current study, RNA silencing was used to knockdown the expression of TaABCC13 in order to evaluate its functional importance in wheat. Transgenic plants with significantly reduced TaABCC13 transcripts in either seeds or roots were selected for further studies. Homozygous RNAi lines K1B4 and K4G7 exhibited 34-22% reduction of the phytic acid content in the mature grains (T4 seeds). These transgenic lines were defective for spike development, as characterized by reduced grain filling and numbers of spikelets. The seeds of transgenic wheat had delayed germination, but the viability of the seedlings was unaffected. Interestingly, early emergence of lateral roots was observed in TaABCC13-silenced lines as compared to non-transgenic lines. In addition, these lines also had defects in metal uptake and development of lateral roots in the presence of cadmium stress. Our results suggest roles of TaABCC13 in lateral root initiation and enhanced sensitivity towards heavy metals. Taken together, these data demonstrate that wheat ABCC13 is functionally important for grain development and plays an important role during detoxification of heavy metals.

  20. Interaction indole-3-acetic acid IAA with lectin Canavalia maritima seeds reveal new function of lectins in plant physiology

    Energy Technology Data Exchange (ETDEWEB)

    Silva Filho, J.C.; Santi-Gadelha, T.; Gadelha, C.A.A.; Delatorre, P. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Teixeira, C.S.; Rocha, B.A.M.; Nobrega, R.B.; Alencar, K.L.L.; Cavada, B.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil)

    2012-07-01

    Full text: Lectins are a class of proteins of non-immune origin characterized by its capability in interacts specifically and reversibly to mono and oligosaccharides. In plant several possible roles have been suggested including their function in seed maturation, cell wall assembly, defense mechanisms, or rhizobial nodulation of legume roots. Nearly all application and proposed of the plant lectins are based on their specific carbohydrate binding. However, it has been reported that lectins from legumes, might interact with other molecules, such as non proteic amino acids and hydrophobic compounds. This study show the first the crystal structure based on molecular replacement of the Canavalia maritima (CML) complexed with IAA correlated with possible role in plant development. Purified CML was dissolved in 20 mMTrisHCl pH 7.6 containing 5 mM IAA, the suitable co-crystals from CML-IAA complex grew in condition 4 of screen I (0.1 M TrisHCl pH 8.5 and 2.0 M ammonium sulfate). This crystal belong to the orthorhombic space group I222 with unit-cell parameters a = 67.1 ; b = 70.7 , c = 97.7 , The structure was refined at 2.1 of resolution to a final R factor of 20.63 % and an R free of 22.54 %. To check the relative position of the IAA molecule in relation to the biological assemble of the CML, the tetrameric structure was generate by crystallographic symmetry. IAA molecules are positioned in the central cavity. The IAA is stabilized by interacting through hydrogen bounds and Van der Waals forces with the amino acids residues Ser 108 and Asn131, and two water molecules. The hydrophilic interactions occur between IAA and side chains of Ser 108, Asn131 and water molecules 26 and 31 by H-bonds. The OG oxygen from Ser108 display H-bonds with O2 and O3 oxygen atoms from IAA, 3.1 and 2.8 respectively. The tetrameric structure of CML complexed with IAA revels which this protein can act during the seedling in plant development. (author)

  1. Ecological niche of Neanderthals from Spy Cave revealed by nitrogen isotopes of individual amino acids in collagen.

    Science.gov (United States)

    Naito, Yuichi I; Chikaraishi, Yoshito; Drucker, Dorothée G; Ohkouchi, Naohiko; Semal, Patrick; Wißing, Christoph; Bocherens, Hervé

    2016-04-01

    This study provides a refined view on the diet and ecological niche of Neanderthals. The traditional view is that Neanderthals obtained most of their dietary protein from terrestrial animals, especially from large herbivores that roamed the open landscapes. Evidence based on the conventional carbon and nitrogen isotopic composition of bulk collagen has supported this view, although recent findings based on plant remains in the tooth calculus, microwear analyses, and small game and marine animal remains from archaeological sites have raised some questions regarding this assumption. However, the lack of a protein source other than meat in the Neanderthal diet may be due to methodological difficulties in defining the isotopic composition of plants. Based on the nitrogen isotopic composition of glutamic acid and phenylalanine in collagen for Neanderthals from Spy Cave (Belgium), we show that i) there was an inter-individual dietary heterogeneity even within one archaeological site that has not been evident in bulk collagen isotopic compositions, ii) they occupied an ecological niche different from those of hyenas, and iii) they could rely on plants for up to ∼20% of their protein source. These results are consistent with the evidence found of plant consumption by the Spy Neanderthals, suggesting a broader subsistence strategy than previously considered.

  2. Conformational transition of FGFR kinase activation revealed by site-specific unnatural amino acid reporter and single molecule FRET

    Science.gov (United States)

    Perdios, Louis; Lowe, Alan R.; Saladino, Giorgio; Bunney, Tom D.; Thiyagarajan, Nethaji; Alexandrov, Yuriy; Dunsby, Christopher; French, Paul M. W.; Chin, Jason W.; Gervasio, Francesco Luigi; Tate, Edward W.; Katan, Matilda

    2017-01-01

    Protein kinases share significant structural similarity; however, structural features alone are insufficient to explain their diverse functions. Thus, bridging the gap between static structure and function requires a more detailed understanding of their dynamic properties. For example, kinase activation may occur via a switch-like mechanism or by shifting a dynamic equilibrium between inactive and active states. Here, we utilize a combination of FRET and molecular dynamics (MD) simulations to probe the activation mechanism of the kinase domain of Fibroblast Growth Factor Receptor (FGFR). Using genetically-encoded, site-specific incorporation of unnatural amino acids in regions essential for activation, followed by specific labeling with fluorescent moieties, we generated a novel class of FRET-based reporter to monitor conformational differences corresponding to states sampled by non phosphorylated/inactive and phosphorylated/active forms of the kinase. Single molecule FRET analysis in vitro, combined with MD simulations, shows that for FGFR kinase, there are populations of inactive and active states separated by a high free energy barrier resulting in switch-like activation. Compared to recent studies, these findings support diversity in features of kinases that impact on their activation mechanisms. The properties of these FRET-based constructs will also allow further studies of kinase dynamics as well as applications in vivo.

  3. Transcriptome profiling and physiological studies reveal a major role for aromatic amino acids in mercury stress tolerance in rice seedlings.

    Directory of Open Access Journals (Sweden)

    Yun-An Chen

    Full Text Available Mercury (Hg is a serious environmental pollution threat to the planet. The accumulation of Hg in plants disrupts many cellular-level functions and inhibits growth and development, but the mechanism is not fully understood. To gain more insight into the cellular response to Hg, we performed a large-scale analysis of the rice transcriptome during Hg stress. Genes induced with short-term exposure represented functional categories of cell-wall formation, chemical detoxification, secondary metabolism, signal transduction and abiotic stress response. Moreover, Hg stress upregulated several genes involved in aromatic amino acids (Phe and Trp and increased the level of free Phe and Trp content. Exogenous application of Phe and Trp to rice roots enhanced tolerance to Hg and effectively reduced Hg-induced production of reactive oxygen species. Hg induced calcium accumulation and activated mitogen-activated protein kinase. Further characterization of the Hg-responsive genes we identified may be helpful for better understanding the mechanisms of Hg in plants.

  4. Conformational transition of FGFR kinase activation revealed by site-specific unnatural amino acid reporter and single molecule FRET

    Science.gov (United States)

    Perdios, Louis; Lowe, Alan R.; Saladino, Giorgio; Bunney, Tom D.; Thiyagarajan, Nethaji; Alexandrov, Yuriy; Dunsby, Christopher; French, Paul M. W.; Chin, Jason W.; Gervasio, Francesco Luigi; Tate, Edward W.; Katan, Matilda

    2017-01-01

    Protein kinases share significant structural similarity; however, structural features alone are insufficient to explain their diverse functions. Thus, bridging the gap between static structure and function requires a more detailed understanding of their dynamic properties. For example, kinase activation may occur via a switch-like mechanism or by shifting a dynamic equilibrium between inactive and active states. Here, we utilize a combination of FRET and molecular dynamics (MD) simulations to probe the activation mechanism of the kinase domain of Fibroblast Growth Factor Receptor (FGFR). Using genetically-encoded, site-specific incorporation of unnatural amino acids in regions essential for activation, followed by specific labeling with fluorescent moieties, we generated a novel class of FRET-based reporter to monitor conformational differences corresponding to states sampled by non phosphorylated/inactive and phosphorylated/active forms of the kinase. Single molecule FRET analysis in vitro, combined with MD simulations, shows that for FGFR kinase, there are populations of inactive and active states separated by a high free energy barrier resulting in switch-like activation. Compared to recent studies, these findings support diversity in features of kinases that impact on their activation mechanisms. The properties of these FRET-based constructs will also allow further studies of kinase dynamics as well as applications in vivo. PMID:28045057

  5. The annual carbon budget for fen and forest in a wetland at Arctic treeline

    Energy Technology Data Exchange (ETDEWEB)

    Rouse, W. R. [McMaster Univ., School of Geography and Geology, Hamilton, ON (Canada); Bello, R. L.; D' Souza, A. [York Univ., Dept. of Geography, Toronto, ON (Canada); Griffis, T. J. [Minnesota Univ., Dept. of Soil, Water and Climate, St. Paul, MN (United States); LaFleur, P. M. [Trent Univ., Dept. of Geography, Peterborough, ON (Canada)

    2002-09-01

    This study of a wetland system at the Arctic treeline compares two carbon budget estimates, one derived from long-term growth rates of organic soil and the other based on shorter-term flux measurements. Result showed that while there was a small loss of carbon from the ecosystem in the case of tundra fen over a period of fifty-three years, the adjacent open subarctic forest showed large gains in atmospheric carbon dioxide during the same period. These longer-term data were supported by shorter-term flux measurements, which also showed carbon loss by the fen and carbon uptake by the forest. The shorter term data indicate that the carbon loss from the fen during this period was attributable to one particularly dry year. The different rates of carbon exchange appear to be controlled by two primary factors. The first is the enhanced development in the fen of a photosynthesis-inhibiting hummock-hollow landscape, while the second is related to warmer and drier average growing season conditions, which inhibit carbon dioxide uptake in the fen and enhances it in the forest. 24 refs., 4 tabs., 3 figs.

  6. Metabolome analysis reveals the effect of carbon catabolite control on the poly(γ-glutamic acid) biosynthesis of Bacillus licheniformis ATCC 9945.

    Science.gov (United States)

    Mitsunaga, Hitoshi; Meissner, Lena; Palmen, Thomas; Bamba, Takeshi; Büchs, Jochen; Fukusaki, Eiichiro

    2016-04-01

    Poly(γ-glutamic acid) (PGA) is a polymer composed of L- and/or D-glutamic acids that is produced by Bacillus sp. Because the polymer has various features as water soluble, edible, non-toxic and so on, it has attracted attention as a candidate for many applications such as foods, cosmetics and so on. However, although it is well known that the intracellular metabolism of Bacillus sp. is mainly regulated by catabolite control, the effect of the catabolite control on the PGA producing Bacillus sp. is largely unknown. This study is the first report of metabolome analysis on the PGA producing Bacillus sp. that reveals the effect of carbon catabolite control on the metabolism of PGA producing Bacillus licheniformis ATCC 9945. Results showed that the cells cultivated in glycerol-containing medium showed higher PGA production than the cells in glucose-containing medium. Furthermore, metabolome analysis revealed that the activators of CcpA and CodY, global regulatory proteins of the intracellular metabolism, accumulated in the cells cultivated in glycerol-containing and glucose-containing medium, respectively, with CodY apparently inhibiting PGA production. Moreover, the cells seemed to produce glutamate from citrate and ammonium using glutamine synthetase/glutamate synthase. Pulsed addition of di-ammonium hydrogen citrate, as suggested by the metabolome result, was able to achieve the highest value so far for PGA production in B. licheniformis.

  7. Aspartic Acid Racemization and Collagen Degradation Markers Reveal an Accumulation of Damage in Tendon Collagen That Is Enhanced with Aging*

    Science.gov (United States)

    Thorpe, Chavaunne T.; Streeter, Ian; Pinchbeck, Gina L.; Goodship, Allen E.; Clegg, Peter D.; Birch, Helen L.

    2010-01-01

    Little is known about the rate at which protein turnover occurs in living tendon and whether the rate differs between tendons with different physiological roles. In this study, we have quantified the racemization of aspartic acid to calculate the age of the collagenous and non-collagenous components of the high strain injury-prone superficial digital flexor tendon (SDFT) and low strain rarely injured common digital extensor tendon (CDET) in a group of horses with a wide age range. In addition, the turnover of collagen was assessed indirectly by measuring the levels of collagen degradation markers (collagenase-generated neoepitope and cross-linked telopeptide of type I collagen). The fractional increase in d-Asp was similar (p = 0.7) in the SDFT (5.87 × 10−4/year) and CDET (5.82 × 10−4/year) tissue, and d/l-Asp ratios showed a good correlation with pentosidine levels. We calculated a mean (±S.E.) collagen half-life of 197.53 (±18.23) years for the SDFT, which increased significantly with horse age (p = 0.03) and was significantly (p < 0.001) higher than that for the CDET (34.03 (±3.39) years). Using similar calculations, the half-life of non-collagenous protein was 2.18 (±0.41) years in the SDFT and was significantly (p = 0.04) lower than the value of 3.51 (±0.51) years for the CDET. Collagen degradation markers were higher in the CDET and suggested an accumulation of partially degraded collagen within the matrix with aging in the SDFT. We propose that increased susceptibility to injury in older individuals results from an inability to remove partially degraded collagen from the matrix leading to reduced mechanical competence. PMID:20308077

  8. Intra-specific diet shift in manila clams (Ruditapes philippinarum) as revealed by carbon and nitrogen stable isotopes and fatty acid biomarker

    Science.gov (United States)

    Suh, Y.; Shin, K.

    2011-12-01

    Manila clams sampled in Seonjae Island, Korea with shell lengths (SL) below 19.76 mm in average showed a significantly depleted carbon and nitrogen isotope values (Pnutrition from both P. tricornutum and aggregated organic matter that consists of dead or decomposed microalgae or other detritus. Bigger size groups (10.92±0.34 mm and 14.81±0.25 mm) obtained most of their energy from P.tricorutum and also from other phytoplankton unlike the biggest size group (21.15±1.02 mm) that feeds mainly on fresh microalgae of all diets fed. This variation in diet reveals that smaller clams mostly inhale dead or decomposed microalgae that sinks on the bottom while the bigger clams uptake more fresh ones that are still alive. This variation in feeding behavior could have been caused by morphological constraints such as limited siphon length. The results suggest that manila clams greater than and below 19.76 mm in average have different feeding behavior and P. tricornutum and I. galbana were the two most preferred diets for manila clams cultured in IFHRI. The result of fatty acid composition of manila clams in relation to size or growth rate suggests that fast growing clams would have rapid metabolism of fatty acids not required by the animals and an accumulation of the essential fatty acids (PUFA). In addition, their higher energy requirement and more active state of development would further diminish lipid reserve of the species.

  9. Proteomic Analysis Revealed the Important Role of Vimentin in Human Cervical Carcinoma HeLa Cells Treated With Gambogic Acid.

    Science.gov (United States)

    Yue, Qingxi; Feng, Lixing; Cao, Biyin; Liu, Miao; Zhang, Dongmei; Wu, Wanying; Jiang, Baohong; Yang, Min; Liu, Xuan; Guo, Dean

    2016-01-01

    Gambogic acid (GA) is an anticancer agent in phase IIb clinical trial in China. In HeLa cells, GA inhibited cell proliferation, induced cell cycle arrest at G2/M phase and apoptosis, as showed by results of MTT assay and flow cytometric analysis. Possible target-related proteins of GA were searched using comparative proteomic analysis (2-DE) and nine proteins at early (3 h) stage together with nine proteins at late (24 h) stage were found. Vimentin was the only target-related protein found at both early and late stage. Results of both 2-DE analysis and Western blotting assay suggested cleavage of vimentin induced by GA. MS/MS analysis of cleaved vimentin peptides indicated possible cleavage sites of vimentin at or near ser51 and glu425. Results of targeted proteomic analysis showed that GA induced change in phosphorylation state of the vimentin head domain (aa51-64). Caspase inhibitors could not abrogate GA-induced cleavage of vimentin. Over-expression of vimentin ameliorated cytotoxicity of GA in HeLa cells. The GA-activated signal transduction, from p38 MAPK, heat shock protein 27 (HSP27), vimentin, dysfunction of cytoskeleton, to cell death, was predicted and then confirmed. Results of animal study showed that GA treatment inhibited tumor growth in HeLa tumor-bearing mice and cleavage of vimentin could be observed in tumor xenografts of GA-treated animals. Results of immunohistochemical staining also showed down-regulated vimentin level in tumor xenografts of GA-treated animals. Furthermore, compared with cytotoxicity of GA in HeLa cells, cytotoxicity of GA in MCF-7 cells with low level of vimentin was weaker whereas cytotoxicity of GA in MG-63 cells with high level of vimentin was stronger. These results indicated the important role of vimentin in the cytotoxicity of GA. The effects of GA on vimentin and other epithelial-to-mesenchymal transition (EMT) markers provided suggestion for better usage of GA in clinic.

  10. O fenómeno de Crowding e as suas implicações na ambliopia

    OpenAIRE

    Yanchik, Nataliya

    2012-01-01

    Fenómeno de Crowding refere-se ao facto da acuidade visual para Optótipos cercados por barras ou outros optótipos, ser pior do que a acuidade visual para os optótipos isolados. Sabe-se que o fenómeno de crowding é mais pronunciado em pessoas com baixa visão, por exemplo amblíopes, do que em pessoas com a visão normal. O objetivo do presente trabalho é perceber os mecanismos subjacentes ao fenómeno de crowding, tanto físicos como óticos ou neurológicos, bem como a sua influência na visão do...

  11. O duplo como fenômeno psíquico

    OpenAIRE

    Marta Regina de Leão D'Agord; Marcos Rafael de Oliveira Barbosa; Rukaya Hasan; Rafael Cavalheiro Neves

    2013-01-01

    Neste trabalho, analisamos um fenômeno psíquico com o qual se ocupa a psicopatologia: o fenômeno do duplo (Doppelgänger), enquanto visão angustiante de si próprio como um outro. Na psicanálise, o duplo pode ser estudado através da concepção do estádio do espelho e do modelo óptico, tais como propostos por Lacan. Entre as elaborações literárias desse fenômeno universal, destacam-se "William Wilson", de E. A. Poe, e "O duplo" de F. Dostoiévski, que se situam no fantástico enquanto gênero literá...

  12. Fenómeno del Niño historia y perspectivas

    OpenAIRE

    Paladines Vélez, Geovanny Antonio; Paladines Vélez, Nelly Betsabeth; Paltán Zhingre, Viviana Marcela; Pazmiño Moreira, Valeria Nathalí; Pedroza Uzhca, Wilson Humberto; Portilla Merino, Paola Patricia; Rivera Robles, César Eduardo; Acurio Páez, Fausto David

    2015-01-01

    Ecuador se ubica en zona de riesgo para la llegada del Fenómeno del Niño, por lo que es necesario estar informados sobre este tema y diferenciar que es la Corriente del Niño (corriente cálida del Pacífico Sudamericano) y el Niño-Oscilación del Sur (patrón climático en el que se producen oscilaciones de la temperatura en dos fases: el Fenómeno del Niño y La Niña). En los años 1997-1998 este fenómeno afectó el 60% del total de la población, con un impacto muy alto en la salud de la ciudadaní...

  13. El fenómeno de la prostitución en la provincia de Palencia

    OpenAIRE

    García Calleja, Rebeca

    2015-01-01

    Este trabajo pretende ser un acercamiento a la realidad sobre el fenómeno de la prostitución y la trata de seres humanos con fines de explotación sexual en la provincia de Palencia. En una primera parte, se presenta el marco teórico en relación con el fenómeno de la prostitución y la trata de seres humanos con fines de explotación sexual, asi como los modelos legislativos existentes sobre el fenómeno de la prostitución y la perspectiva político – legal adoptada por España. Y, en la segund...

  14. FORMATION OF Fe-N COMPOUNDS BY LASER NITRIDATION IN AN ATMOSPHERIC AMBIENT

    Institute of Scientific and Technical Information of China (English)

    Y.L. Yang; F.J. Sun; D. Zhang

    2003-01-01

    The formation of Fe-N compounds by laser nitriding in an atmospheric ambient wasreported. By CW-CO2 laser irradiation on pure ferrite iron in the atmospheric am-bient, Fe-N compounds (including Fe2N, Fe3N and Fe4N) are formed as a result of alaser-enhanced and temperature-enhanced reactions. The samples were analyzed withX-ray diffraction. It is found that the laser power density, scanning speed and nitro-gen temperature are the main factors influencing the formation of Fe-N compounds.Nitrogen can be activated by pre-heating at some temperature. Nitrogen activationand sample surface melting by CW-CO2 laser greatly enhance the reaction betweenthe sample surface and nitrogen beam. After annealing at 500℃ for 3h, some Fe2Nand Fe3N converted into more stable Fe4N.

  15. Catalytic analysis of APOBEC3G involving real-time NMR spectroscopy reveals nucleic acid determinants for deamination.

    Directory of Open Access Journals (Sweden)

    Keisuke Kamba

    Full Text Available APOBEC3G (A3G is a single-stranded DNA-specific cytidine deaminase that preferentially converts cytidine to uridine at the third position of triplet cytosine (CCC hotspots. A3G restricts the infectivity of viruses, such as HIV-1, by targeting CCC hotspots scattered through minus DNA strands, reverse-transcribed from genomic RNA. Previously, we developed a real-time NMR method and elucidated the origin of the 3'→5' polarity of deamination of DNA by the C-terminal domain of A3G (CD2, which is a phenomenon by which a hotspot located closer to the 5'-end is deaminated more effectively than one less close to the 5'-end, through quantitative analysis involving nonspecific binding to and sliding along DNA. In the present study we applied the real-time NMR method to analyze the catalytic activity of CD2 toward DNA oligonucleotides containing a nucleotide analog at a single or multiple positions. Analyses revealed the importance of the sugar and base moieties throughout the consecutive 5 nucleotides, the CCC hotspot being positioned at the center. It was also shown that the sugar or base moieties of the nucleotides outside this 5 nucleotide recognition sequence are also relevant as to CD2's activity. Analyses involving DNA oligonucleotides having two CCC hotspots linked by a long sequence of either deoxyribonucleotides, ribonucleotides or abasic deoxyribonucleotides suggested that the phosphate backbone is required for CD2 to slide along the DNA strand and to exert the 3'→5' polarity. Examination of the effects of different salt concentrations on the 3'→5' polarity indicated that the higher the salt concentration, the less prominent the 3'→5' polarity. This is most likely the result of alleviation of sliding due to a decrease in the affinity of CD2 with the phosphate backbone at high salt concentrations. We also investigated the reactivity of substrates containing 5-methylcytidine (5mC or 5-hydroxymethylcytidine, and found that A3G exhibited low

  16. Single-Amino Acid Modifications Reveal Additional Controls on the Proton Pathway of [FeFe]-Hydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Cornish, Adam J.; Ginovska, Bojana; Thelen, Adam; da Silva, Julio C. S.; Soares, Thereza A.; Raugei, Simone; Dupuis, Michel; Shaw, Wendy J.; Hegg, Eric L.

    2016-06-07

    The proton pathway of [FeFe]-hydrogenase is essential for enzymatic H2 production and oxidation and is composed of four residues and a modeled water molecule. Recently, a computational analysis of this pathway revealed that the solvent-exposed residue of the pathway (Glu282) could form hydrogen bonds to two residues outside of the pathway (Arg286 and Ser320), implicating that these residues could function in regulating proton transfer. Substituting Arg286 with leucine eliminates hydrogen bonding with Glu282 and results in a 2.5-fold enhancement in H2 production activity, suggesting that Arg286 serves an important role in controlling the rate of proton delivery. In contrast, substitution of Ser320 with alanine reduces the rate approximately 5-fold, implying that it either acts as a member of the pathway or influences Glu282 to enable proton transfer. Interestingly, QM/MM and molecular dynamics calculations indicate that Ser320 does not play an electronic or structural role. QM calculations also estimate that including Ser320 in the pathway does not significantly change the barrier to proton movement, providing further support for its role as a member of the proton pathway. While further studies are needed to quantify the role of Ser320, collectively, these data provide evidence that the enzyme scaffold plays a significant role in modulating the activity of the enzyme, demonstrating that the rate of intraprotein proton transfer can be accelerated, particularly in a non-biological context. This work was supported by the DOE Great Lakes Bioenergy Research Center (DOE BER Office of Science, DE-FC02-07ER64494). In addition, support from the DOE Office of Science Early Career Research Program through the Office of Basic Energy Sciences (WJS, BGP, SR) is gratefully acknowledged. Computational resources were provided at W. R. Wiley Environmental Molecular Science Laboratory (EMSL), a national scientific user facility sponsored by the Department of Energy’s Office of

  17. X-ray structure of Pur-alpha reveals a Whirly-like fold and an unusual nucleic-acid binding surface.

    Science.gov (United States)

    Graebsch, Almut; Roche, Stéphane; Niessing, Dierk

    2009-11-03

    The PUR protein family is a distinct and highly conserved class that is characterized by its sequence-specific RNA- and DNA-binding. Its best-studied family member, Pur-alpha, acts as a transcriptional regulator, as host factor for viral replication, and as cofactor for mRNP localization in dendrites. Pur-alpha-deficient mice show severe neurologic defects and die after birth. Nucleic-acid binding by Pur-alpha is mediated by its central core region, for which no structural information is available. We determined the x-ray structure of residues 40 to 185 from Drosophila melanogaster Pur-alpha, which constitutes a major part of the core region. We found that this region contains two almost identical structural motifs, termed "PUR repeats," which interact with each other to form a PUR domain. DNA- and RNA-binding studies confirmed that PUR domains are indeed functional nucleic-acid binding domains. Database analysis show that PUR domains share a fold with the Whirly class of nucleic-acid binding proteins. Structural analysis combined with mutational studies suggest that a PUR domain binds nucleic acids through two independent surface regions involving concave beta-sheets. Structure-based sequence alignment revealed that the core region harbors a third PUR repeat at its C terminus. Subsequent characterization by small-angle x-ray scattering (SAXS) and size-exclusion chromatography indicated that PUR repeat III mediates dimerization of Pur-alpha. Surface envelopes calculated from SAXS data show that the Pur-alpha dimer consisting of repeats I to III is arranged in a Z-like shape. This unexpected domain organization of the entire core domain of Pur-alpha has direct implications for ssDNA/ssRNA and dsDNA binding.

  18. Characterization of VuMATE1 expression in response to iron nutrition and aluminum stress reveals adaptation of rice bean (Vigna umbellata to acid soils through cis regulation

    Directory of Open Access Journals (Sweden)

    Meiya eLiu

    2016-04-01

    Full Text Available Rice bean (Vigna umbellata VuMATE1 appears to be constitutively expressed at vascular system but root apex, and Al stress extends its expression to root apex. Whether VuMATE1 participates in both Al tolerance and Fe nutrition, and how VuMATE1 expression is regulated is of great interest. In this study, the role of VuMATE1 in Fe nutrition was characterized through in planta complementation assays. The transcriptional regulation of VuMATE1 was investigated through promoter analysis and promoter-GUS reporter assays. The results showed that the expression of VuMATE1 was regulated by Al stress but not Fe status. Complementation of frd3-1 with VuMATE1 under VuMATE1 promoter could not restore phenotype, but restored with 35SCaMV promoter. Immunostaining of VuMATE1 revealed abnormal localization of VuMATE1 in vasculature. In planta GUS reporter assay identified Al-responsive cis-acting elements resided between -1228 and -574 bp. Promoter analysis revealed several cis-acting elements, but transcription is not simply regulated by one of these elements. We demonstrated that cis regulation of VuMATE1 expression is involved in Al tolerance mechanism, while not involved in Fe nutrition. These results reveal the evolution of VuMATE1 expression for better adaptation of rice bean to acidic soils where Al stress imposed but Fe deficiency pressure released.

  19. Fen1 mutations that specifically disrupt its interaction with PCNA cause aneuploidy-associated cancer

    Institute of Scientific and Technical Information of China (English)

    Li Zheng; Sankar Mitra; Qin Huang; Kemp H Kernstine; Gerd P Pfeifer; Binghui Shen; Huifang Dai; Muralidhar L Hegde; Mian Zhou; Zhigang Guo; Xiwei Wu; Jun WU; Lei Su; Xueyan Zhong

    2011-01-01

    DNA replication and repair are critical processes for all living organisms to ensure faithful duplication and transmission of genetic information. Flap endonuclease 1 (Feni), a structure-specific nuclease, plays an important role in multiple DNA metabolic pathways and maintenance of genome stability. Human FEN1 mutations that impair its exonuclease activity have been linked to cancer development. FEN1 interacts with multiple proteins, including proliferation cell nuclear antigen (PCNA), to form various functional complexes. Interactions with these proteins are considered to be the key molecular mechanisms mediating FEN1's key biological functions. The current challenge is to experimentally demonstrate the biological consequence of a specific interaction without compromising other functions of a desired protein. To address this issue, we established a mutant mouse model harboring a FEN1 point mutation (F343A/F344A, FFAA), which specifically abolishes the FEN1/PCNA interaction. We show that the FFAA mutation causes defects in RNA primer removal and long-patch base excision repair, even in the heterozygous state, resulting in numerous DNA breaks. These breaks activate the G2/M checkpoint protein, Chk1, and induce neartetraploid aneuploidy, commonly observed in human cancer, consequently elevating the transformation frequency. Consistent with this, inhibition of aneupioidy formation by a Chk1 inhibitor significantly suppressed the cellular transformation. WT/FFAA FEN1 mutant mice develop aneuploidy-associated cancer at a high frequency. Thus, this study establishes an exemplary case for investigating the biological significance of protein-protein interactions by knock-in of a point mutation rather than knock-out of a whole gene.

  20. NMR-based metabolomics reveals that conjugated double bond content and lipid storage efficiency in HepG2 cells are affected by fatty acid cis/trans configuration and chain length

    DEFF Research Database (Denmark)

    Najbjerg, Heidi; Young, Jette F; Bertram, Hanne Christine S.

    2011-01-01

    -11), linoleic acid (C18:2), or palmitic acid (C16:0), and multivariate data analysis revealed a strong effect of fatty acid on the lipophilic metabolite fraction. Inspection of the spectra revealed that the difference between the observed responses could be ascribed to the appearance of resonances......:0), myristic acid (C14:0), or palmitic acid (C16:0), an effect of fatty acid length was also evident, and data indicated that short-chain fatty acids (C4C6) are immediately converted, whereas mediumlong-chain fatty acids (C1216) are incorporated into triglycerides and deposited in the cells. In conclusion......In the present study the metabolic response to various fatty acids was investigated in HepG2 cells by using a 1HNMRbased approach. To elucidate the effect of cis/trans configuration, the cells were exposed to either oleic acid (C18:1 cis-9), elaidic acid (C18:1 trans-9), vaccenic acid (C18:1 trans...

  1. Fate and Transport of Road Salt During Snowmelt Through a Calcareous Fen: Kampoosa Bog, Stockbridge, Massachusetts

    Science.gov (United States)

    Rhodes, A. L.; Guswa, A. J.; Pufall, A.

    2007-12-01

    Kampoosa Bog is the largest and most ecologically diverse calcareous lake-basin fen in Massachusetts. Situated within a 4.7 km2 drainage basin, the open fen (approx. 20 acres) consists of a floating mat of sedges (incl. Carex aquatilis and Cladium mariscoides) that overlie peat and lake clay deposits. Mineral weathering of marble bedrock within the drainage basin supplies highly alkaline ground and surface waters to the fen basin. The natural chemistry has been greatly altered by road salt runoff from the Massaschusetts Turnpike, and in question is whether disturbance from the Turnpike and a gas pipline has facilitated aggressive growth by the invasive species Phragmites australis. Considered to be one of the most significant rare species habitats in the state, Massachusetts has designated Kampoosa Bog an Area of Critical Environmental Concern, and a committee representing several local, regional, and state agencies, organizations, and citizens manages the wetland. The purpose of this study is to characterize the hydrologic and chemical response of the wetland during snowmelt events to understand the fate and movement of road salt (NaCl). Concentrations of Na and Cl in the fen groundwater are greatest close to the Turnpike. Concentrations decrease with distance downstream but are still greatly elevated relative to sites upstream of the Turnpike. During snowmelt events, the fen's outlet shows a sharp rise in Na and Cl concentrations at the onset of melting that is soon diluted by the added meltwater. The Na and Cl flux, however, is greatest at peak discharge, suggesting that high-flow events are significant periods of export of dissolved salts from the fen. Pure dissolution of rock salt produces an equal molar ratio between Na and Cl, and sodium and chloride imbalances in stream and ground waters suggest that ~20% of the Na is stored on cation exchange sites within the peat. The largest imbalances between Na and Cl occur deeper within the peat, where the peat is

  2. El perfil de crecimiento de un fenómeno económico

    OpenAIRE

    Espasa, Antoni

    1991-01-01

    EI perfil de crecimiento de un fenómeno económico que se observa mensualmente viene reflejado en la serie de crecimientos mensuales, que denominamos crecímíentos básicos. Esta serie en sí misma es de escasa utilidad como indicador ya que suele oscilar enormemente. Un buen indicador de crecimiento debe mostrar pocas oscilaciones, siempre relativo a la naturaleza del fenómeno, y no estar retrasado con la serie de crecimientos básicos. El desfase se evita utilizando tasas centradas. Además, por ...

  3. Compostos fenólicos totais e taninos condensados em frutas nativas do cerrado

    Directory of Open Access Journals (Sweden)

    Wesley Silveira Rocha

    2011-12-01

    Full Text Available As frutas nativas do cerrado têm despertado ultimamente interesse crescente, devido às suas propriedades nutricionais e funcionais aliadas ao potencial para agregar valor e conservar a biodiversidade deste bioma. Muitos compostos fenólicos apresentam capacidade antioxidante de neutralizar a atividade de radicais livres gerados no organismo, que estão associados a diversas doenças crônico-degenerativas. O objetivo deste trabalho foi avaliar a eficiência de três soluções extratoras (acetona a 70 %, etanol a 95 % e metanol a 99,8 % e determinar os teores de compostos fenólicos em 10 espécies de frutas nativas do cerrado, utilizando o método de Folin-Ciocalteou para compostos fenólicos totais e o método da vanilina para taninos condensados. A acetona a 70 % mostrou-se como o melhor solvente extrator de compostos fenólicos totais e taninos condensados em frutos de Pouteria gardneriana, Eugenia dysenterica, E. klostzchiana, E. punicifolia, Plinia edulis, Campomanesia sp., fenólicos totais de Brosimium gaudichaudii e taninos condensados de Jaracatia spinosa. O etanol a 95 % foi mais eficiente na extração de fenólicos totais de Jaracatia spinosa e taninos condensados de Brosimium gaudichaudii; o metanol a 99,8 % foi mais eficiente na extração de taninos condensados de Eugenia dysenterica. Os teores de compostos fenólicos totais variaram entre 90 e 327 mg de ácido gálico equivalente por 100g de polpa para as espécies E. dysenterica e E. punicifolia, respectivamente. Os teores de taninos condensados variaram entre 4 e 291 mg de catequina equivalente por 100 g de polpa para as espécies E. dysenterica e E. calcyna, respectivamente. As espécies de frutas do cerrado, avaliadas neste estudo, podem ser consideradas boas fontes de compostos fenólicos totais, sendo que a natureza específica dos diferentes tipos deve ser avaliada em estudos futuros.

  4. Performance of a constructed fen peatland: Reclamation of oil sands landscapes

    Science.gov (United States)

    Price, J. S.

    2013-12-01

    Wetlands cover >60% of the landscape in the Athabasca oils sands development region. These are predominantly fen peatlands, that rely to varying extent on base-rich surface- and/or ground-water derived from adjacent mineral lands. Large areas of peatland are removed by surface stripping to access the bitumen. Reclamation of post-mined landscapes to peatland has not previously been attempted. Groundwater modeling was used to guide design choices on the optimal geometry, placement (layering) and hydraulic properties of locally available materials; these include processed tailings sand, as well peat and forest soils from newly developed lease areas. The constructed system comprises a ~3 ha fen with 2 m of peat and an adjacent upland specifically designed to supply the requisite water to maintain suitable hydrological conditions. The upland is primarily tailings sand covered by a forest soil. The constructed fen/upland system was set within a ~30 ha basin that was reclaimed using standard techniques and materials, and supplements water inputs to the designed system. Both fen and upland were placed at water contents well below equilibrium levels, so there was concern about the wetland function during the years following construction. However, in its first year following construction (2013), a higher than normal snowpack flooded the system, but by surface inflow rather than seepage from the upland. Ground-ice in the fen limited the general infiltration and percolation of meltwater into the peat, although fortuitously a localized recharge pipe developed through thermal erosion and substantially recharged the fen. Water was redistributed beneath the fen through a highly permeable sublayer (petroleum coke) designed for this purpose, and created artesian pressures. Backflow into the upland also resulted, although much of the upland remains well below design water contents. Modification of the upland soils by plowing, and development of local recharge basins, is expected to

  5. El fenómeno del acoso laboral entre los trabajadores de la universidad

    OpenAIRE

    Justicia,Fernando Justicia; Benítez Muñoz,Juan L.; Fernández de Haro, Eduardo; Berbén,Ana G.

    2007-01-01

    El objetivo del artículo es realizar una descripción del fenómemo mobbing -acoso laboral- en el contexto de la universidad. Los trabajos realizadossobre este problema no son muy prolíficos lo que puede explicar la gran dificultad para caracterizar el fenómeno en el ámbito universitario. En el presente trabajo presentamos los niveles de incidencia del acoso laboral entre la población universitaria, los tipos de acoso más frecuentes y los efectos producidos en las víctimas, con la finalidad de ...

  6. Microbiología alimentaria y fenómenos "paranormales" en la historia

    Directory of Open Access Journals (Sweden)

    José Miguel Soriano del Castillo

    2014-12-01

    Full Text Available A lo largo de la historia han existido fenómenos aparentemente inexplicables cuyos resultados han originado muertes, milagros, juicios por brujería e incluso ganancias y pérdidas de batallas militares. En este artículo se realiza una inspección microbiológica-histórica en donde algunos microorganismos (Claviceps purpurea, Fusarium sporotrichioides, Serratia marcescens y Stachybotrys chartarum, pueden ser los hipotéticos causantes de algunos de estos fenómenos.

  7. Método de musicalización de un fenómeno monitorizado

    OpenAIRE

    Ribas i Xirgo, Lluís; Vacchina, Silvana

    2007-01-01

    La presente invención concierne a un método de musicalización de un fenómeno monitorizado, sobre la base de una serie de datos representativa de dicho fenómeno. Dicho método comprende las siguientes etapas: obtener uno o más valores de una o más variables a partir de un tratamiento matemático de dicha serie de datos; asignar una característica musical básica a dicho valor; generar, con ayuda de unos medios programables, una composición musical basada en una estructura general determinada por ...

  8. Identities among actin-encoding cDNAs of the Nile tilapia (Oreochromis niloticus and other eukaryote species revealed by nucleotide and amino acid sequence analyses

    Directory of Open Access Journals (Sweden)

    Andréia B. Poletto

    2008-01-01

    Full Text Available Actin-encoding cDNAs of Nile tilapia (Oreochromis niloticus were isolated by RT-PCR using total RNA samples of different tissues and further characterized by nucleotide sequencing and in silico amino acid (aa sequence analysis. Comparisons among the actin gene sequences of O. niloticus and those of other species evidenced that the isolated genes present a high similarity to other fish and other vertebrate actin genes. The highest nucleotide resemblance was observed between O. niloticus and O. mossambicus a-actin and b-actin genes. Analysis of the predicted aa sequences revealed two distinct types of cytoplasmic actins, one cardiac muscle actin type and one skeletal muscle actin type that were expressed in different tissues of Nile tilapia. The evolutionary relationships between the Nile tilapia actin genes and diverse other organisms is discussed.

  9. Transcriptome and membrane fatty acid analyses reveal different strategies for responding to permeating and non-permeating solutes in the bacterium Sphingomonas wittichii

    Directory of Open Access Journals (Sweden)

    Johnson David R

    2011-11-01

    opposite effect and decreased after perturbation with PEG8000. Conclusions A combination of growth assays, transcriptome profiling, and membrane fatty acid analyses revealed that permeating and non-permeating solutes trigger different adaptive responses in strain RW1, suggesting these solutes affect cells in fundamentally different ways. Future work is now needed that connects these responses with the responses observed in more realistic scenarios of soil desiccation.

  10. Diversity in the structures and ligand-binding sites of nematode fatty acid and retinol-binding proteins revealed by Na-FAR-1 from Necator americanus.

    Science.gov (United States)

    Rey-Burusco, M Florencia; Ibáñez-Shimabukuro, Marina; Gabrielsen, Mads; Franchini, Gisela R; Roe, Andrew J; Griffiths, Kate; Zhan, Bin; Cooper, Alan; Kennedy, Malcolm W; Córsico, Betina; Smith, Brian O

    2015-11-01

    Fatty acid and retinol-binding proteins (FARs) comprise a family of unusual α-helix rich lipid-binding proteins found exclusively in nematodes. They are secreted into host tissues by parasites of plants, animals and humans. The structure of a FAR protein from the free-living nematode Caenorhabditis elegans is available, but this protein [C. elegans FAR-7 (Ce-FAR-7)] is from a subfamily of FARs that does not appear to be important at the host/parasite interface. We have therefore examined [Necator americanus FAR-1 (Na-FAR-1)] from the blood-feeding intestinal parasite of humans, N. americanus. The 3D structure of Na-FAR-1 in its ligand-free and ligand-bound forms, determined by NMR (nuclear magnetic resonance) spectroscopy and X-ray crystallography respectively, reveals an α-helical fold similar to Ce-FAR-7, but Na-FAR-1 possesses a larger and more complex internal ligand-binding cavity and an additional C-terminal α-helix. Titration of apo-Na-FAR-1 with oleic acid, analysed by NMR chemical shift perturbation, reveals that at least four distinct protein-ligand complexes can be formed. Na-FAR-1 and possibly other FARs may have a wider repertoire for hydrophobic ligand binding, as confirmed in the present study by our finding that a range of neutral and polar lipids co-purify with the bacterially expressed recombinant protein. Finally, we show by immunohistochemistry that Na-FAR-1 is present in adult worms with a tissue distribution indicative of possible roles in nutrient acquisition by the parasite and in reproduction in the male.

  11. Diversity in the structures and ligand-binding sites of nematode fatty acid and retinol-binding proteins revealed by Na-FAR-1 from Necator americanus

    Science.gov (United States)

    Rey-Burusco, M. Florencia; Ibáñez-Shimabukuro, Marina; Gabrielsen, Mads; Franchini, Gisela R.; Roe, Andrew J.; Griffiths, Kate; Zhan, Bin; Cooper, Alan; Kennedy, Malcolm W.; Córsico, Betina; Smith, Brian O.

    2015-01-01

    Fatty acid and retinol-binding proteins (FARs) comprise a family of unusual α-helix rich lipid-binding proteins found exclusively in nematodes. They are secreted into host tissues by parasites of plants, animals and humans. The structure of a FAR protein from the free-living nematode Caenorhabditis elegans is available, but this protein [C. elegans FAR-7 (Ce-FAR-7)] is from a subfamily of FARs that does not appear to be important at the host/parasite interface. We have therefore examined [Necator americanus FAR-1 (Na-FAR-1)] from the blood-feeding intestinal parasite of humans, N. americanus. The 3D structure of Na-FAR-1 in its ligand-free and ligand-bound forms, determined by NMR (nuclear magnetic resonance) spectroscopy and X-ray crystallography respectively, reveals an α-helical fold similar to Ce-FAR-7, but Na-FAR-1 possesses a larger and more complex internal ligand-binding cavity and an additional C-terminal α-helix. Titration of apo-Na-FAR-1 with oleic acid, analysed by NMR chemical shift perturbation, reveals that at least four distinct protein–ligand complexes can be formed. Na-FAR-1 and possibly other FARs may have a wider repertoire for hydrophobic ligand binding, as confirmed in the present study by our finding that a range of neutral and polar lipids co-purify with the bacterially expressed recombinant protein. Finally, we show by immunohistochemistry that Na-FAR-1 is present in adult worms with a tissue distribution indicative of possible roles in nutrient acquisition by the parasite and in reproduction in the male. PMID:26318523

  12. MALDI Mass Spectrometry Imaging of Lipids and Gene Expression Reveals Differences in Fatty Acid Metabolism between Follicular Compartments in Porcine Ovaries

    Directory of Open Access Journals (Sweden)

    Svetlana Uzbekova

    2015-03-01

    Full Text Available In mammals, oocytes develop inside the ovarian follicles; this process is strongly supported by the surrounding follicular environment consisting of cumulus, granulosa and theca cells, and follicular fluid. In the antral follicle, the final stages of oogenesis require large amounts of energy that is produced by follicular cells from substrates including glucose, amino acids and fatty acids (FAs. Since lipid metabolism plays an important role in acquiring oocyte developmental competence, the aim of this study was to investigate site-specificity of lipid metabolism in ovaries by comparing lipid profiles and expression of FA metabolism-related genes in different ovarian compartments. Using MALDI Mass Spectrometry Imaging, images of porcine ovary sections were reconstructed from lipid ion signals for the first time. Cluster analysis of ion spectra revealed differences in spatial distribution of lipid species among ovarian compartments, notably between the follicles and interstitial tissue. Inside the follicles analysis differentiated follicular fluid, granulosa, theca and the oocyte-cumulus complex. Moreover, by transcript quantification using real time PCR, we showed that expression of five key genes in FA metabolism significantly varied between somatic follicular cells (theca, granulosa and cumulus and the oocyte. In conclusion, lipid metabolism differs between ovarian and follicular compartments.

  13. Solution Structure of the Tandem Acyl Carrier Protein Domains from a Polyunsaturated Fatty Acid Synthase Reveals Beads-on-a-String Configuration

    KAUST Repository

    Trujillo, Uldaeliz

    2013-02-28

    The polyunsaturated fatty acid (PUFA) synthases from deep-sea bacteria invariably contain multiple acyl carrier protein (ACP) domains in tandem. This conserved tandem arrangement has been implicated in both amplification of fatty acid production (additive effect) and in structural stabilization of the multidomain protein (synergistic effect). While the more accepted model is one in which domains act independently, recent reports suggest that ACP domains may form higher oligomers. Elucidating the three-dimensional structure of tandem arrangements may therefore give important insights into the functional relevance of these structures, and hence guide bioengineering strategies. In an effort to elucidate the three-dimensional structure of tandem repeats from deep-sea anaerobic bacteria, we have expressed and purified a fragment consisting of five tandem ACP domains from the PUFA synthase from Photobacterium profundum. Analysis of the tandem ACP fragment by analytical gel filtration chromatography showed a retention time suggestive of a multimeric protein. However, small angle X-ray scattering (SAXS) revealed that the multi-ACP fragment is an elongated monomer which does not form a globular unit. Stokes radii calculated from atomic monomeric SAXS models were comparable to those measured by analytical gel filtration chromatography, showing that in the gel filtration experiment, the molecular weight was overestimated due to the elongated protein shape. Thermal denaturation monitored by circular dichroism showed that unfolding of the tandem construct was not cooperative, and that the tandem arrangement did not stabilize the protein. Taken together, these data are consistent with an elongated beads-on-a-string arrangement of the tandem ACP domains in PUFA synthases, and speak against synergistic biocatalytic effects promoted by quaternary structuring. Thus, it is possible to envision bioengineering strategies which simply involve the artificial linking of multiple ACP

  14. Solution structure of the tandem acyl carrier protein domains from a polyunsaturated fatty acid synthase reveals beads-on-a-string configuration.

    Directory of Open Access Journals (Sweden)

    Uldaeliz Trujillo

    Full Text Available The polyunsaturated fatty acid (PUFA synthases from deep-sea bacteria invariably contain multiple acyl carrier protein (ACP domains in tandem. This conserved tandem arrangement has been implicated in both amplification of fatty acid production (additive effect and in structural stabilization of the multidomain protein (synergistic effect. While the more accepted model is one in which domains act independently, recent reports suggest that ACP domains may form higher oligomers. Elucidating the three-dimensional structure of tandem arrangements may therefore give important insights into the functional relevance of these structures, and hence guide bioengineering strategies. In an effort to elucidate the three-dimensional structure of tandem repeats from deep-sea anaerobic bacteria, we have expressed and purified a fragment consisting of five tandem ACP domains from the PUFA synthase from Photobacterium profundum. Analysis of the tandem ACP fragment by analytical gel filtration chromatography showed a retention time suggestive of a multimeric protein. However, small angle X-ray scattering (SAXS revealed that the multi-ACP fragment is an elongated monomer which does not form a globular unit. Stokes radii calculated from atomic monomeric SAXS models were comparable to those measured by analytical gel filtration chromatography, showing that in the gel filtration experiment, the molecular weight was overestimated due to the elongated protein shape. Thermal denaturation monitored by circular dichroism showed that unfolding of the tandem construct was not cooperative, and that the tandem arrangement did not stabilize the protein. Taken together, these data are consistent with an elongated beads-on-a-string arrangement of the tandem ACP domains in PUFA synthases, and speak against synergistic biocatalytic effects promoted by quaternary structuring. Thus, it is possible to envision bioengineering strategies which simply involve the artificial linking of

  15. Tissue-specific inactivation of type 2 deiodinase reveals multilevel control of fatty acid oxidation by thyroid hormone in the mouse.

    Science.gov (United States)

    Fonseca, Tatiana L; Werneck-De-Castro, Joao Pedro; Castillo, Melany; Bocco, Barbara M L C; Fernandes, Gustavo W; McAninch, Elizabeth A; Ignacio, Daniele L; Moises, Caio C S; Ferreira, Alexander R; Ferreira, Alexandre; Gereben, Balázs; Bianco, Antonio C

    2014-05-01

    Type 2 deiodinase (D2) converts the prohormone thyroxine (T4) to the metabolically active molecule 3,5,3'-triiodothyronine (T3), but its global inactivation unexpectedly lowers the respiratory exchange rate (respiratory quotient [RQ]) and decreases food intake. Here we used FloxD2 mice to generate systemically euthyroid fat-specific (FAT), astrocyte-specific (ASTRO), or skeletal-muscle-specific (SKM) D2 knockout (D2KO) mice that were monitored continuously. The ASTRO-D2KO mice also exhibited lower diurnal RQ and greater contribution of fatty acid oxidation to energy expenditure, but no differences in food intake were observed. In contrast, the FAT-D2KO mouse exhibited sustained (24 h) increase in RQ values, increased food intake, tolerance to glucose, and sensitivity to insulin, all supporting greater contribution of carbohydrate oxidation to energy expenditure. Furthermore, FAT-D2KO animals that were kept on a high-fat diet for 8 weeks gained more body weight and fat, indicating impaired brown adipose tissue (BAT) thermogenesis and/or inability to oxidize the fat excess. Acclimatization of FAT-D2KO mice at thermoneutrality dissipated both features of this phenotype. Muscle D2 does not seem to play a significant metabolic role given that SKM-D2KO animals exhibited no phenotype. The present findings are unique in that they were obtained in systemically euthyroid animals, revealing that brain D2 plays a dominant albeit indirect role in fatty acid oxidation via its sympathetic control of BAT activity. D2-generated T3 in BAT accelerates fatty acid oxidation and protects against diet-induced obesity.

  16. Promotion of CO oxidation on the Fe/N X clusters embedded graphene

    Science.gov (United States)

    Zhao, Ming Yu; Zhao, Ru Meng; Niu, Meng Meng; Li, Wei; Ma, Ya Qiang; Li, Yi; Tang, Ya Nan; Dai, Xian Qi

    2017-03-01

    CO catalytic oxidation on the two-dimensional (2D) Fe/N X clusters embedded graphene (G) (X = 4, 3, 2, 1) with D 4h, C 2v, C 2h, and C S symmetries is investigated using the first-principle method. Fe/N2-G system with C 2h symmetry facilitates the O2 adsorption. The strong interaction between the Fe atom and O2 in Fe/N2-G system can be contributed from the high energy of Fe's d_z^2 orbit. The CO oxidation reaction on Fe/N2-G system has a small energy barrier (0.43 eV) by the Langmuir-Hinshelwood (LH) mechanism (CO + O2 → OOCO → CO2 + Oads), which would be useful in evaluating the reactivity of Fe catalyst and serving as a good candidate for efficient non-noble metal catalyst. The results provide valuable guidance on selecting catalysts of low cost and superior activity to fabricate graphene-based materials.

  17. The effect of habitat fragmentation and abiotic factors on fen plant occurrence

    NARCIS (Netherlands)

    Soomers, H.; Karssenberg, D.J.; Verhoeven, J.T.A.; Verweij, P.A.; Wassen, M.J.

    2013-01-01

    Human landscape modification has led to habitat fragmentation for many species. Habitat fragmentation, leading to isolation, decrease in patch size and increased edge effect, is observed in fen ecosystems that comprise many endangered plant species. However, until now it has remained unclear whether

  18. Preventing acidification and eutrophication in rich fens: Water level management as a solution?

    NARCIS (Netherlands)

    Cusell, C.

    2014-01-01

    For this thesis, I examined the effects of the re-introduction of fluctuating surface water levels in freshwater wetlands. These systems, and especially the rich fen wetlands that I focused on, often consist of a mosaic of aquatic, semi-aquatic and terrestrial vegetation types, including many biodiv

  19. Water level fluctuations in rich fens: an assessment of ecological benefits and drawbacks

    NARCIS (Netherlands)

    I.S. Mettrop

    2015-01-01

    For the proper functioning of endangered biodiverse rich fens, base-rich and nutrient-poor (mesotrophic) conditions are required to prevent succession towards Sphagnum-dominated peatlands. Unfortunately, water- and soil quality of many European wetlands are negatively affected by changes in hydrolog

  20. Eutrophication triggers contrasting multilevel feedbacks on litter accumulation and decomposition in fens

    NARCIS (Netherlands)

    Emsens, W. -J.; Aggenbach, C. J. S.; Grootjans, A. P.; Nfor, E. E.; Schoelynck, J.; Struyf, E.; van Diggelen, R.

    2016-01-01

    Eutrophication is a major threat for the persistence of nutrient-poor fens, as multilevel feedbacks on decomposition rates could trigger carbon loss and increase nutrient cycling. Here, we experimentally investigate the effects of macronutrient (NPK) enrichment on litter quality of six species of se

  1. Phase Transformations and Phase Equilibria in the Fe-N System at Temperatures below 573 K

    DEFF Research Database (Denmark)

    Malinov, S.; Böttger, A.J.; Mittemeijer, E.J.;

    2001-01-01

    The phase transformations of homogeneous Fe-N alloys of nitrogen contents from 10 to 26 at. pct were investigated by means of X-ray diffraction analysis upon aging in the temperature range from 373 to 473 K. It was found that precipitation of alpha double prime-Fe16N2 below 443 K does not only oc...

  2. Methods of limiting willow shrub re-growth after initial removal on fen meadows

    NARCIS (Netherlands)

    Klimkowska, Agata; Dzierza, Paulina; Kotowski, Wiktor; Brzezinska, Kamila

    2010-01-01

    Shrub removal is commonly used for management and restoration of species-rich fen meadows. A common problem after initial shrub cutting of willow is a vigorous re-sprouting and quick re-growth. In this paper we test experimentally what is an effective management option, limiting the re-growth of wil

  3. Structure and Magnetic Properties of Fe-N Films Prepared by Dual Ion Beam Sputtering

    Institute of Scientific and Technical Information of China (English)

    诸葛兰剑; 吴雪梅; 汤乃云; 叶春兰; 姚伟国

    2001-01-01

    Fe-N films were prepared on Si substrate by dual ion beam sputtering (DIBS). It is of the films were investigated by a vibrating sample magnetometer (VSM). The structure of the films is insensitive to the ratios of N2/Ar in main ion source(MIS), and is mainly influenced by the substrate temperature (Ts).``

  4. Partitioning of habitat effects casts light on the decline of the fen orchid, Liparis loeselii

    DEFF Research Database (Denmark)

    Andersen, Dagmar Kappel; Ejrnæs, Rasmus; Minter, Martine Olesen;

    2015-01-01

    Liparis loeselii is a rare and declining orchid species restricted to rich fens in the northern hemisphere. Suggested reasons for the decline are habitat destruction, eutrophication, altered hydrology and scrub encroachment after termination of traditional management such as grazing and hay makin...

  5. Prospects of fen restoration in relation to changing land use-An example from central Poland

    NARCIS (Netherlands)

    Klimkowska, Agata; Dzierża, Paulina; Grootjans, Ab P.; Kotowski, Wiktor; Diggelen, Rudy Van

    2010-01-01

    We carried out an eco-hydrological analysis to evaluate the most important effects of land use changes on the hydrological functioning of a fen system in Poland. We measured water levels (hydraulic heads) and water flow along a transect through the study area and also analysed land use changes using

  6. Prospects of fen restoration in relation to changing land use—An example from central Poland

    NARCIS (Netherlands)

    Klimkowska, A.; Dzierza, P.; Grootjans, A.P.; Kotowski, W.; Diggelen, R.

    2010-01-01

    We carried out an eco-hydrological analysis to evaluate the most important effects of land use changes on the hydrological functioning of a fen system in Poland. We measured water levels (hydraulic heads) and water flow along a transect through the study area and also analysed land use changes using

  7. Fen-meadow succession in relation to spatial and temporal differences in hydrological and soil conditions

    NARCIS (Netherlands)

    Hoek, van der D.; Sykora, K.V.

    2006-01-01

    Question: In fen meadows with Junco-Molinion plant communities, falling groundwater levels may not lead to a boosted above-ground biomass production if limitation of nutrients persists. Instead, depending on drainage intensity and microtopography, acidification may trigger a shift into drier and mor

  8. O duplo como fenômeno psíquico

    Directory of Open Access Journals (Sweden)

    Marta Regina de Leão D'Agord

    2013-09-01

    Full Text Available Neste trabalho, analisamos um fenômeno psíquico com o qual se ocupa a psicopatologia: o fenômeno do duplo (Doppelgänger, enquanto visão angustiante de si próprio como um outro. Na psicanálise, o duplo pode ser estudado através da concepção do estádio do espelho e do modelo óptico, tais como propostos por Lacan. Entre as elaborações literárias desse fenômeno universal, destacam-se "William Wilson", de E. A. Poe, e "O duplo" de F. Dostoiévski, que se situam no fantástico enquanto gênero literário. Em nossa análise do fenômeno do duplo, realizamos uma comparação entre modelos literários e psicanalíticos.

  9. All-atom molecular dynamics simulations reveal significant differences in interaction between antimycin and conserved amino acid residues in bovine and bacterial bc1 complexes.

    Science.gov (United States)

    Kokhan, Oleksandr; Shinkarev, Vladimir P

    2011-02-02

    Antimycin A is the most frequently used specific and powerful inhibitor of the mitochondrial respiratory chain. We used all-atom molecular dynamics (MD) simulations to study the dynamic aspects of the interaction of antimycin A with the Q(i) site of the bacterial and bovine bc(1) complexes embedded in a membrane. The MD simulations revealed considerable conformational flexibility of antimycin and significant mobility of antimycin, as a whole, inside the Q(i) pocket. We conclude that many of the differences in antimycin binding observed in high-resolution x-ray structures may have a dynamic origin and result from fluctuations of protein and antimycin between multiple conformational states of similar energy separated by low activation barriers, as well as from the mobility of antimycin within the Q(i) pocket. The MD simulations also revealed a significant difference in interaction between antimycin and conserved amino acid residues in bovine and bacterial bc(1) complexes. The strong hydrogen bond between antimycin and conserved Asp-228 (bovine numeration) was observed to be frequently broken in the bacterial bc(1) complex and only rarely in the bovine bc(1) complex. In addition, the distances between antimycin and conserved His-201 and Lys-227 were consistently larger in the bacterial bc(1) complex. The observed differences could be responsible for a weaker interaction of antimycin with the bacterial bc(1) complex.

  10. The manipulation of auxin in the abscission zone cells of Arabidopsis flowers reveals that indoleacetic acid signaling is a prerequisite for organ shedding.

    Science.gov (United States)

    Basu, Manojit M; González-Carranza, Zinnia H; Azam-Ali, Sayed; Tang, Shouya; Shahid, Ahmad Ali; Roberts, Jeremy A

    2013-05-01

    A number of novel strategies were employed to examine the role of indoleacetic acid (IAA) in regulating floral organ abscission in Arabidopsis (Arabidopsis thaliana). Analysis of auxin influx facilitator expression in β-glucuronidase reporter plants revealed that AUXIN RESISTANT1, LIKE AUX1, and LAX3 were specifically up-regulated at the site of floral organ shedding. Flowers from mutants where individual family members were down-regulated exhibited a reduction in the force necessary to bring about petal separation; however, the effect was not additive in double or quadruple mutants. Using the promoter of a polygalacturonase (At2g41850), active primarily in cells undergoing separation, to drive expression of the bacterial genes iaaL and iaaM, we have shown that it is possible to manipulate auxin activity specifically within the floral organ abscission zone (AZ). Analysis of petal breakstrength reveals that if IAA AZ levels are reduced, shedding takes place prematurely, while if they are enhanced, organ loss is delayed. The At2g41850 promoter was also used to transactivate the gain-of-function AXR3-1 gene in order to disrupt auxin signaling specifically within the floral organ AZ cells. Flowers from transactivated lines failed to shed their sepals, petals, and anthers during pod expansion and maturity, and these organs frequently remained attached to the plant even after silique desiccation and dehiscence had taken place. These observations support a key role for IAA in the regulation of abscission in planta and reveal, to our knowledge for the first time, a requirement for a functional IAA signaling pathway in AZ cells for organ shedding to take place.

  11. Seasonal and inter-annual variation in ecosystem scale methane emission from a boreal fen

    Science.gov (United States)

    Rinne, Janne; Li, Xuefei; Raivonen, Maarit; Peltola, Olli; Sallantaus, Tapani; Haapanala, Sami; Smolander, Sampo; Alekseychik, Pavel; Aurela, Mika; Korrensalo, Aino; Mammarella, Ivan; Tuittila, Eeva-Stiina; Vesala, Timo

    2016-04-01

    Northern wetlands are one of the major sources of atmospheric methane. We have measured ecosystem scale methane emissions from a boreal fen continuously since 2005. The site is an oligotrophic fen in boreal vegetation zone situated in Siikaneva wetland complex in Southern Finland. The mean annual temperature in the area is 3.3°C and total annual precipitation 710 mm. We have conducted the methane emission measurements by the eddy covariance method. Additionally we have measured fluxes of carbon dioxide, water vapor, and sensible heat together with a suite of other environmental parameters. We have analyzed this data alongside with a model run with University of Helsinki methane model. The measured fluxes show generally highest methane emission in late summers coinciding with the highest temperatures in saturated peat zone. During winters the fluxes show small but detectable emission despite the snow and ice cover on the fen. More than 90% of the annual methane emission occurs in snow-free period. The methane emission and peat temperature are connected in exponential manner in seasonal scales, but methane emission does not show the expected behavior with water table. The lack of water table position dependence also contrasts with the spatial variation across microtopography. There is no systematic variation in sub-diurnal time scale. The general seasonal cycle in methane emission is captured well with the methane model. We will show how well the model reproduces the temperature and water table position dependencies observed. The annual methane emission is typically around 10 gC m-2. This is a significant part of the total carbon exchange between the fen and the atmosphere and about twice the estimated carbon loss by leaching from the fen area. The inter-annual variability in the methane emission is modest. The June-September methane emissions from different years, comprising most of the annual emission, correlates positively with peat temperature, but not with

  12. Fenóis totais, flavonoides totais e atividade antioxidante de Selaginella convoluta (Arn. Spring (Selaginellaceae

    Directory of Open Access Journals (Sweden)

    Pedro Guilherme Sousa de Sá

    2012-12-01

    Full Text Available Selaginella convoluta é uma espécie conhecida no Nordeste do Brasil como “jericó”, e bastante utilizada na medicina popular para tratamento de doenças. Este estudo teve como objetivo determinar o teor de compostos fenólicos e avaliar a atividade antioxidante in vitro do extrato etanólico e das frações obtidas por partição de S. convoluta. O conteúdo de fenóis totais foi determinado pelo método de Folin-Ciocalteu. O teor de flavonoides totais também foi avaliado. A atividade antioxidante dos extratos foi avaliada usando o método do sequestro do radical DPPH e inibição da auto-oxidação do sistema β-caroteno-ácido linoleico e comparada com os compostos de referência ácido ascórbico, BHA, BHT, quercetina e pirogalol. O conteúdo fenólico total foi de 209,90 ± 19,84 e 61,13 ± 2,50 mg equivalente de ácido gálico/g para os extratos AcOEt e EEB, respectivamente. O conteúdo de flavonoides totais foi de 155,70 ± 6,21 e 62,13 ± 4,10 para os dois extratos, respectivamente. Os extratos AcOEt e EEB apresentaram boas atividades antioxidantes. BHA foi o antioxidante mais efetivo, com um valor de IC50 de 1,62 ± 0,69 µg/mL. Os resultados obtidos mostram que S. convoluta pode ser uma boa fonte de compostos fenólicos antioxidantes. Estudos posteriores serão realizados para se chegar ao isolamento e identificação dos principais constituintes fenólicos dos extratos.

  13. The Influence of FEN-1 Gene on Cell Cycle and Genetic Stability%FEN-1基因对细胞周期和遗传稳定性的影响

    Institute of Scientific and Technical Information of China (English)

    石斌山; 余应年; 蔡朱男; 沈炳辉

    2001-01-01

    FEN-1 is essential in the cell replication, repair and in themaintenance of cellular genetic stability. In this report, it was verfied that FEN-1 antisense mRNA fragment was expressed in the cell line FL-FEN-1-, constructed in our lab, blocking FEN-1 gene expression. It was found by the flow cytometer analysis that the cell cycle of FL-FEN-1- cells was delayed in the S-phase DNA synthesis process and arrested in G1 phase. In a mutation assay, based on the shuttle-plasmid pZ189, the spontaneous mutation frequency of SupF tRNA gene in the plasmid in the FL-FEN-1-cells was 19.1×104, while it was 2.9×104 and 3.0×104 in the control cells FL and FL-M, respectively. Further study showed that nontargeted mutation frequency of the FL-FEN-1- cell induced by MNNG was almost the same as the control, indicating that the mutants derived from the block of FEN- 1 gene and the nontargeted mutants may be formed through different passways. The FL-FEN-1 cells exhibit increased sensitivity to alkylating agent MNNG.%结构特异性核酸酶FEN-1在DNA复制和修复,以及维持细胞遗传稳定性方面都起着重要作用。采用RT-PCR方法,证实了FEN-1基因阻断细胞(FL-FEN-1-)通过FEN-1反义mRNA片段的表达,阻断了FEN-1基因。应用流式细胞仪对FL-FEN-1-细胞进行细胞周期分析,发现FL-FEN-1-细胞进入S期DNA合成的过程被延缓,并发生了G1期的阻滞。在由穿梭质粒pZ189介导的突变试验中,质粒在FL-FEN-1-细胞中复制后,其SupFtRNA基因的自发突变频率为19.1×104,而对照细胞FL和FL-M细胞分别为2.9×104和3.0×104,但FLFEN-1-细胞经甲基硝基亚硝基胍(MNNG)诱发后的非定标突变频率与对照细胞并无明显差异,这表明由FEN-1阻断造成的突变频率升高与细胞在受低浓度MNNG攻击后发生的非定标突变可能通过不同的途径形成。FL-FEN-1-细胞对MNNG的敏感性高于对照细胞。

  14. Reverse transcription quantitative PCR revealed persistency of thermophilic lactic acid bacteria metabolic activity until the end of the ripening of Emmental cheese.

    Science.gov (United States)

    Falentin, Hélène; Henaff, Nadine; Le Bivic, Pierre; Deutsch, Stéphanie-Marie; Parayre, Sandrine; Richoux, Romain; Sohier, Daniele; Thierry, Anne; Lortal, Sylvie; Postollec, Florence

    2012-02-01

    For Emmental manufacture two kinds of adjunct culture are added: (i) thermophilic lactic acid bacteria (starters) such as Lactobacillus helveticus (LH), and Streptococcus thermophilus (ST) growing the first day of the manufacture and (ii) ripening culture. ST and LH have a key role in curd acidification and proteolysis at the beginning of the manufacture but are considered to be lyzed for a great part of them at the ripening step. The aim of this work was to assess the metabolic activity of these bacteria throughout manufacture and ripening. During Emmental cheesemaking, LH and ST were subjected to i) population quantification by numerations and by quantitative PCR (qPCR) ii) reverse transcription (RT) Temporal Temperature Gel Electrophoresis (TTGE) iii) transcript quantification by RT-qPCR targeting 16S rRNA, tuf and groL mRNAs to evaluate bacterial metabolic activity. During ripening, ST and LH numerations showed a 2.5 log(10) loss of culturability whereas qPCR on pelleted cells revealed only one log(10) of decrease for both of these species. 10(9) ST and 10(8) LH cells/g of cheese still remained. They contained a stable number of 16S transcript and at least 10(6) copies of mRNAs per 10(9) cells until the end of ripening. These results prove the unexpected persistency of thermophilic lactic acid bacteria starters (ST and LH) metabolic activity until the end of ripening and open new perspectives in term of their involvement in the quality of cheeses during ripening.

  15. Novel Insights Into The Mode of Inhibition of Class A SHV-1 Beta-Lactamases Revealed by Boronic Acid Transition State Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    W Ke; J Sampson; C Ori; F Prati; S Drawz; C Bethel; R Bonomo; F van den Akker

    2011-12-31

    Boronic acid transition state inhibitors (BATSIs) are potent class A and C {beta}-lactamase inactivators and are of particular interest due to their reversible nature mimicking the transition state. Here, we present structural and kinetic data describing the inhibition of the SHV-1 {beta}-lactamase, a clinically important enzyme found in Klebsiella pneumoniae, by BATSI compounds possessing the R1 side chains of ceftazidime and cefoperazone and designed variants of the latter, compounds 1 and 2. The ceftazidime and cefoperazone BATSI compounds inhibit the SHV-1 {beta}-lactamase with micromolar affinity that is considerably weaker than their inhibition of other {beta}-lactamases. The solved crystal structures of these two BATSIs in complex with SHV-1 reveal a possible reason for SHV-1's relative resistance to inhibition, as the BATSIs adopt a deacylation transition state conformation compared to the usual acylation transition state conformation when complexed to other {beta}-lactamases. Active-site comparison suggests that these conformational differences might be attributed to a subtle shift of residue A237 in SHV-1. The ceftazidime BATSI structure revealed that the carboxyl-dimethyl moiety is positioned in SHV-1's carboxyl binding pocket. In contrast, the cefoperazone BATSI has its R1 group pointing away from the active site such that its phenol moiety moves residue Y105 from the active site via end-on stacking interactions. To work toward improving the affinity of the cefoperazone BATSI, we synthesized two variants in which either one or two extra carbons were added to the phenol linker. Both variants yielded improved affinity against SHV-1, possibly as a consequence of releasing the strain of its interaction with the unusual Y105 conformation.

  16. Composição fenólica e atividade antioxidante de resíduos agroindustriais Phenolic composition and antioxidant activity of agroindustrial residues

    Directory of Open Access Journals (Sweden)

    Priscilla Siqueira Melo

    2011-06-01

    Full Text Available Atualmente, são produzidas milhões de toneladas de resíduos provenientes do processamento agroindustrial. Muitos deles são ricos em compostos bioativos sendo potenciais fontes naturais dessas substâncias. Assim, este trabalho teve como objetivo avaliar o teor de compostos fenólicos totais, a atividade antioxidante e a composição fenólica de três resíduos gerados por agroindústrias brasileiras: bagaço de uva Isabel (BI (Vitis labrusca, bagaço de uva Verdejo (BV (Vitis vinifera e bagaço de goiaba (BG (Psidium guajava. Os resultados do teor de compostos fenólicos totais (mg GAE g-1 encontrados nos extratos etanólicos e aquosos dos resíduos foram, respectivamente: BV (20,94±0,46; 8,03±0,43> BI (16,57±0,19; 4,41±0,01> BG (3,41±0,09; 1,88±0,06. Alta atividade antioxidante, principalmente em BV e BI, foi verificada nos ensaios realizados (ABTS ●, DPPH ● e auto-oxidação do sistema beta-caroteno/ácido linoléico. Uma forte correlação positiva entre atividade antioxidante e o teor de compostos fenólicos totais foi encontrada. Os compostos fenólicos encontrados, por cromatografia gasosa com espectrometria de massas (CG-EM, foram: ácido gálico, epicatequina, quercetina (BV, BI e BG; ácido isovanílico (BI, BG; ácido p-cumárico (BI; ácido caféico e resveratrol (BV, BI. Esses resultados mostram que os resíduos agroindustriais analisados, particularmente os vinícolas, são ricos em substâncias bioativas e podem ser explorados pela indústria de alimentos e farmacêutica.Nowadays, the agro-industrial processing produces millions of tons of wastes. Many of them are rich in bioactive compounds, being a potential natural source of these substances. This study aimed to evaluate the content of total phenolics, antioxidant activity and phenolic composition of residues generated by three Brazilian agribusiness: Isabel grape pomace (PI (Vitis labrusca, Verdejo grape pomace (PV (Vitis vinifera and guava pomace (PG (Psidium

  17. Kinetic analysis of bifidobacterial metabolism reveals a minor role for succinic acid in the regeneration of NAD+ through its growth-associated production.

    Science.gov (United States)

    Van der Meulen, Roel; Adriany, Tom; Verbrugghe, Kristof; De Vuyst, Luc

    2006-08-01

    Several strains belonging to the genus Bifidobacterium were tested to determine their abilities to produce succinic acid. Bifidobacterium longum strain BB536 and Bifidobacterium animalis subsp. lactis strain Bb 12 were kinetically analyzed in detail using in vitro fermentations to obtain more insight into the metabolism and production of succinic acid by bifidobacteria. Changes in end product formation in strains of Bifidobacterium could be related to the specific rate of sugar consumption. When the specific sugar consumption rate increased, relatively more lactic acid and less acetic acid, formic acid, and ethanol were produced, and vice versa. All Bifidobacterium strains tested produced small amounts of succinic acid; the concentrations were not more than a few millimolar. Succinic acid production was found to be associated with growth and stopped when the energy source was depleted. The production of succinic acid contributed to regeneration of a small part of the NAD+, in addition to the regeneration through the production of lactic acid and ethanol.

  18. Global transcription analysis of Krebs tricarboxylic acid cycle mutants reveals an alternating pattern of gene expression and effects on hypoxic and oxidative genes.

    Science.gov (United States)

    McCammon, Mark T; Epstein, Charles B; Przybyla-Zawislak, Beata; McAlister-Henn, Lee; Butow, Ronald A

    2003-03-01

    To understand the many roles of the Krebs tricarboxylic acid (TCA) cycle in cell function, we used DNA microarrays to examine gene expression in response to TCA cycle dysfunction. mRNA was analyzed from yeast strains harboring defects in each of 15 genes that encode subunits of the eight TCA cycle enzymes. The expression of >400 genes changed at least threefold in response to TCA cycle dysfunction. Many genes displayed a common response to TCA cycle dysfunction indicative of a shift away from oxidative metabolism. Another set of genes displayed a pairwise, alternating pattern of expression in response to contiguous TCA cycle enzyme defects: expression was elevated in aconitase and isocitrate dehydrogenase mutants, diminished in alpha-ketoglutarate dehydrogenase and succinyl-CoA ligase mutants, elevated again in succinate dehydrogenase and fumarase mutants, and diminished again in malate dehydrogenase and citrate synthase mutants. This pattern correlated with previously defined TCA cycle growth-enhancing mutations and suggested a novel metabolic signaling pathway monitoring TCA cycle function. Expression of hypoxic/anaerobic genes was elevated in alpha-ketoglutarate dehydrogenase mutants, whereas expression of oxidative genes was diminished, consistent with a heme signaling defect caused by inadequate levels of the heme precursor, succinyl-CoA. These studies have revealed extensive responses to changes in TCA cycle function and have uncovered new and unexpected metabolic networks that are wired into the TCA cycle.

  19. Interaction of Di-2-pyridylketone 2-pyridine Carboxylic Acid Hydrazone and Its Copper Complex with BSA: Effect on Antitumor Activity as Revealed by Spectroscopic Studies.

    Science.gov (United States)

    Li, Cuiping; Huang, Tengfei; Fu, Yun; Liu, Youxun; Zhou, Sufeng; Qi, Zhangyang; Li, Changzheng

    2016-04-28

    The drug, di-2-pyridylketone-2-pyridine carboxylic acid hydrazone (DPPCAH) and its copper complex (DPPCAH-Cu) exhibit significant antitumor activity. However, the mechanism of their pharmacological interaction with the biological molecule bovine serum albumin (BSA) remains poorly understood. The present study elucidates the interactions between the drug and BSA through MTT assays, spectroscopic methods and molecular docking analysis. Our results indicate that BSA could attenuate effect on the cytotoxicity of DPPCAH, but not DPPCAH-Cu. Data from fluorescence quenching measurements demonstrated that both DPPCAH and DPPCAH-Cu could bind to BSA, with a reversed effect on the environment of tryptophan residues in polarity. CD spectra revealed that the DPPCAH-Cu exerted a slightly stronger effect on the secondary structure of BSA than DPPCAH. The association constant of DPPCAH with BSA was greater than that of DPPCAH-Cu. Docking studies indicated that the binding of DPPCAH to BSA involved a greater number of hydrogen bonds compared to DPPCAH-Cu. The calculated distances between bound ligands and tryptophans in BSA were in agreement with fluorescence resonance energy transfer results. Thus, the binding affinity of the drug (DPPCAH or DPPCAH-Cu) with BSA partially contributes to its antitumor activity; the greater the drug affinity is to BSA, the less is its antitumor activity.

  20. Microarray Analysis Reveals Higher Gestational Folic Acid Alters Expression of Genes in the Cerebellum of Mice Offspring—A Pilot Study

    Directory of Open Access Journals (Sweden)

    Subit Barua

    2015-01-01

    Full Text Available Folate is a water-soluble vitamin that is critical for nucleotide synthesis and can modulate methylation of DNA by altering one-carbon metabolism. Previous studies have shown that folate status during pregnancy is associated with various congenital defects including the risk of aberrant neural tube closure. Maternal exposure to a methyl supplemented diet also can alter DNA methylation and gene expression, which may influence the phenotype of offspring. We investigated if higher gestational folic acid (FA in the diet dysregulates the expression of genes in the cerebellum of offspring in C57BL/6 J mice. One week before gestation and throughout the pregnancy, groups of dams were supplemented with FA either at 2 mg/kg or 20 mg/kg of diet. Microarray analysis was used to investigate the genome wide gene expression profile in the cerebellum from day old pups. Our results revealed that exposure to the higher dose FA diet during gestation dysregulated expression of several genes in the cerebellum of both male and female pups. Several transcription factors, imprinted genes, neuro-developmental genes and genes associated with autism spectrum disorder exhibited altered expression levels. These findings suggest that higher gestational FA potentially dysregulates gene expression in the offspring brain and such changes may adversely alter fetal programming and overall brain development.

  1. Specific polyunsaturated fatty acids modulate lipid delivery and oocyte development in C. elegans revealed by molecular-selective label-free imaging

    Science.gov (United States)

    Chen, Wei-Wen; Yi, Yung-Hsiang; Chien, Cheng-Hao; Hsiung, Kuei-Ching; Ma, Tian-Hsiang; Lin, Yi-Chun; Lo, Szecheng J.; Chang, Ta-Chau

    2016-08-01

    Polyunsaturated fatty acids (PUFAs) exhibit critical functions in biological systems and their importance during animal oocyte maturation has been increasingly recognized. However, the detailed mechanism of lipid transportation for oocyte development remains largely unknown. In this study, the transportation of yolk lipoprotein (lipid carrier) and the rate of lipid delivery into oocytes in live C. elegans were examined for the first time by using coherent anti-Stokes Raman scattering (CARS) microscopy. The accumulation of secreted yolk lipoprotein in the pseudocoelom of live C. elegans can be detected by CARS microscopy at both protein (~1665 cm‑1) and lipid (~2845 cm‑1) Raman bands. In addition, an image analysis protocol was established to quantitatively measure the levels of secreted yolk lipoprotein aberrantly accumulated in PUFA-deficient fat mutants (fat-1, fat-2, fat-3, fat-4) and PUFA-supplemented fat-2 worms (the PUFA add-back experiments). Our results revealed that the omega-6 PUFAs, not omega-3 PUFAs, play a critical role in modulating lipid/yolk level in the oocytes and regulating reproductive efficiency of C. elegans. This work demonstrates the value of using CARS microscopy as a molecular-selective label-free imaging technique for the study of PUFA regulation and oocyte development in C. elegans.

  2. Fe and N diffusion in nitrogen-rich FeN measured using neutron reflectometry

    Indian Academy of Sciences (India)

    Mukul Gupta; A Gupta; A Wildes; T Gutberlet

    2008-11-01

    Grazing incidence neutron reflectometry provides an opportunity to measure the depth profile of a thin film sample with a resolution <1 nm, in a non-destructive way. In this way the diffusion across the interfaces can also be measured. In addition, neutrons have contrast among the isotopes, making it feasible to measure the self-diffusion. In the present work, the isotope multilayers of [FeN/57 FeN]10 and [FeN/Fe15N]10 were prepared using magnetron sputtering and self-diffusion of Fe and N was investigated. It was found that N diffusion is slower compared to Fe and does not follow the atomic size dependence.

  3. CH4 emissions from two floodplain fens of differing nutrient status

    Science.gov (United States)

    Stanley, Kieran; Heppell, Catherine; Belyea, Lisa; Baird, Andrew

    2014-05-01

    Floodplain fens emit large amounts of CH4 in comparison with ombrotrophic bogs. Little is known about the effect of fluvial nitrogen (N) and phosphorus (P) on CH4 dynamics in fens, although N and P affect carbon (C) dynamics indirectly in other environments by controlling plant growth and root exudate release, as well as by altering microbial biomass and decomposition rates. This study aimed to compare CH4 emissions from two floodplain fen sites which differ in nutrient status, Sutton Fen (52°45'N 001°30'E) and Strumpshaw Fen (52°36'N 001°27'E), in the Norfolk Broadland of England. Sutton and Strumpshaw Fen are under conservation management and both sites have water levels that vary within a few decimetres above and below the surface. The sites are dominated by reed (Phragmites australis). Areas within the fens where the reed was cut in 2009 were chosen for this study. Average plant height and mean aboveground biomass were significantly greater at Strumpshaw (107.2 ± 7.8 cm and 1578 ± 169 g m-2, respectively) than Sutton (56.5 ± 5.1 cm and 435 ± 42 g m-2) as were mean foliar N and P contents (21.8 ± 1.5 g kg-1 and 2.0 ± 0.2 g kg-1 at Strumpshaw, versus 16.3 ± 1.5 g kg-1 and 1.1 ± 0.1 g kg-1 at Sutton). Foliar NPK ratios showed Strumpshaw to be N limited, whereas Sutton was both N and P limited, depending on microsite. Surface peat N and P contents were also greater at Strumpshaw (28.3 ± 0.35 g kg-1 and 0.78 ± 0.02 g kg-1, respectively) than Sutton (18.32 ± 0.87 g kg-1 and 0.43 ± 0.1 g kg-1). These results indicate clear differences in nutrient status between the two sites despite their geographical proximity and other similarities. CH4 emissions were monitored monthly between 19th June 2012 and 2nd September 2013 using tall static chambers and glass funnel-traps, the latter for ebullition. Steady fluxes did not follow a clear seasonal pattern; however, emission was greatest in the summer months. Strumpshaw had a greater range in efflux (0.25 to 134

  4. Desempleo entre los jornaleros agrícolas, un fenómeno emergente

    Directory of Open Access Journals (Sweden)

    Antonieta Barrón

    2013-01-01

    Full Text Available Este artículo tiene como propósito presentar un fenómeno no planteado en el estudio de mercados de trabajo agrícolas y empleo rural, se cuestiona la definición de desem- pleo, y se plantea cómo esta definición, asumida por el inegi, se aplica en los mercados de trabajo formales pero no en los no formales, los agrícolas. Se hacen comparaciones entre los niveles nacional y rural para concluir con los estudios de caso que refuerzan la tesis inicial, el aumento del desempleo en los mercados de trabajo rurales. A lo largo del trabajo se resaltan las diferencias por sexo y se conlcuye que el desempleo rural afecta más a las mujeres que los hombres, fenómeno contrario al de nivel nacional.

  5. Formation dynamics of FeN thin films on Cu(100)

    KAUST Repository

    Heryadi, Dodi

    2012-01-01

    To investigate the structural and magnetic properties of thin films of FeN we have performed ab initio molecular dynamics simulations of their formation on Cu(100) substrates. The iron nitride layers exhibit a p4gm(2 × 2) reconstruction and order ferromagnetically in agreement with experiment. We establish the dynamics and time scale of the film formation as a function of the film thickness. The process is split in two phases: formation of almost flat FeN layers and optimization of the distance to the substrate. Our calculated magnetic moments are 1.67 μ B, 2.14 μ B, and 2.21 μ B for one, two, and three monolayers of iron nitride. © 2011 Elsevier B.V. All rights reserved.

  6. Theoretical study on the interaction of pristine, defective and strained graphene with Fen and Nin (n = 13, 38, 55) clusters

    Science.gov (United States)

    Song, Wei; Jiao, Menggai; Li, Kai; Wang, Ying; Wu, Zhijian

    2013-11-01

    The structural and electronic properties of Fen and Nin (n = 13, 38, 55) clusters interacting with pristine, defective and strained graphene are investigated by means of self-consistent charge density-functional tight binding (SCC-DFTB) method. The cluster size dependence, defect influence, and strain effect are discussed. We found that the defects play an important role in stabilizing metal clusters by forming metal-carbon σ bonds. Large charge redistribution of Fen compared to Nin lead to stronger interaction in Fen@graphene. The results suggested that tuning the morphological level of the substrate defect and cluster size could affect the catalytic activity of the metal cluster.

  7. Efecto antioxidante y antihipertensivo de diferentes compuestos fenólicos del aceite de oliva virgen 'in vitro'

    OpenAIRE

    González Gómez-Navarro, Cecilia

    2009-01-01

    Consta de 2 estudios in vitro:1. La valoración de la capacidad antioxidante de 19 compuestos fenólicos del AOV, mediante la Lag Phase de los dienos conjugados de la LDL inducida por Cu2+. Los compuestos fenólicos con mayor actividad antioxidante son, en orden decreciente: luteolina, rutina, hidroxitirosol, oleuropeína y 3,4-DHPEA-EDA. La mezcla de estos 5 compuestos incrementa en 1.8 veces la suma de la Lag Phase de cada uno de los compuestos fenólicos individualmente (p

  8. Ajuste de metodologia da eletroforese de proteínas para obtenção de fenótipos isoenzimáticos de moranga Adjustment of the methodology of protein electrophoresis to obtain isozymatic phenotypes of pumpkin

    Directory of Open Access Journals (Sweden)

    Antonio Teixeira do Amaral Júnior

    1994-01-01

    Full Text Available Modificações no procedimento eletroforético foram introduzidas para uma satisfatória obtenção de fenótipos isoenzimáticos de moranga (Cucurbita maxima Duchesne. Extratos de folhas definitivas de oito acessos de moranga foram submetidos à análise eletroforética para revelação dos seguintes sistemas: esterase (EST; fosfatase ácida (ACP; transaminase do glutamato oxaloacetato (GOT, desidrogenase do malato (MDH e peroxidase (PO. Os resultados apontaram a ineficiência do tampão extrator utilizado e satisfatória qualidade do gel de amido de milho nas resoluções dos sistemas EST, ACP, GOT e MDH. Para o sistema PO, adequado efeito de peneiramento molecular só foi possível com a utilização do amido hidrolisado de batata (Sigma. Ajustes no tempo de cozimento do gel, manuseio da corrente elétrica, preparo de soluções corantes e tempo de revelação indicaram os melhores protocolos ao pro-cedimento eletroforético.Changes in the electrophoresis procedures were introduced to obtain a better isozymatic phenotypes of pumpkin (Cucurbita maxima Duchesne. Extracts of eight access of pumpkin's leaves were subjected to electrophoresis analysis in order to reveal the following systems: esterase (EST, acid phosphatase (ACP, glutamate oxaloacetate transaminase (GOT, malato dehydrogenase (MDH and peroxidase (PO. The results pointed out the inefficiency of the extractor buffer used, and the satisfactory quality of maize starch gel electrophoresis in the resolution of EST, ACP, GOT and MDH systems. For PO system a better effect of "molecular sieving" was only possible when potato starch gel (Sigma was used. Adjusting the starch cooking time, handling the electric current, preparing the staining solutions and revealing time indicated the best protocol to the electrophoresis process.

  9. The structure and magnetic properties of Fe-N thin films

    Institute of Scientific and Technical Information of China (English)

    周剑平; 李丹; 顾有松; 常香荣; 赵春生; 李福燊; 乔利杰; 田中卓; 宋庆山; 方光旦

    2002-01-01

    200 nm Fe-N thin films deposited on glass substrates by RF sputtering were vacuum annealed at 250-350℃ under 12000 A/m magnetic field. Heat treatment was effective in improving the soft magnetic properties of the Fe-N film. When the nitrogen content was in the range of 5-7 at. %,the thin films consisted of α′ + α" after heat treatment and had excellent soft magnetic properties of 4πMs = 2.4 T, Hc < 80 A/m, μr = 1500 under 2-10 MHz. The properties of the films meet the needs of a write head material used in the dual element GMR/inductive heads. The fromation mechanism and lattice constants of the α′ phase in Fe-N thin film are different from Jack's results obtained from γ→α′transformation in bulk samples. The linear relationship between a, c and Ca'N for thin film was obtained asc = 2. 866+ 1.559Ca'N,a = 2.866 + 0.181Ca'N.``

  10. Restoring sedges and mosses into frost heaving iron fens, San Juan Mountains, Colorado

    Directory of Open Access Journals (Sweden)

    R.A. Chimner

    2011-08-01

    Full Text Available Rare iron fens in the San Juan Mountains of Colorado are frequently in poor condition due to mining, roads and ditches, which have left much of the fen completely bare of vegetation. Natural revegetation is slow to occur in the bare areas because of severe frost heave in the cold mountain climate. Therefore, experimental revegetation plots were conducted in a factorial design with mulching and no mulching, crossed with moss diaspores, sedge transplants, and moss and sedge combined. Mulching influenced surface soil temperatures by reducing the midday highs and increasing the night-time lows, which decreased the frequency and amount of frost heave. Peat moisture also modified frost heave, with the greatest frost heaving occurring near 75 % peat moisture content (water table 10–20 cm below the surface and the least when soils were either wetter or drier. Moss survival was dependent on mulch, with no moss surviving in plots without mulch. Mulching also increased sedge transplant survival. In summary, mulching significantly increased the success of vegetation restoration efforts for frost heave areas in mountain fens.

  11. El fenómeno de envejecimiento de los asfaltos Asphalts’ aging phenomenon

    Directory of Open Access Journals (Sweden)

    Reyes Freddy

    2010-12-01

    Full Text Available En este trabajo se presenta una revisión actualizada a los resultados del estudio de los procesos de envejecimiento de los asfaltos, encontrados por diversos investigadores, con el fin de profundizar en la comprensión de este fenómeno complejo. Los antecedentes demuestran la evolución del estudio del fenómeno de envejecimiento de los asfaltos, considerado inicialmente como un proceso de endurecimiento físico y progresivamente reconocido como un fenómeno complejo con repercusiones en la durabilidad y las propiedades fisicoquímicas del asfalto. Este documento pretende ser una guía para el emprendimiento de futuras investigaciones relacionadas con el desarrollo de nuevos asfaltos y mezclas asfálticas con propiedades mejoradas.This work presents a state of the art revision of the results from studies of asphalt aging found by researchers aimed at deepening understanding of this complex phenomenon. The background shows the evolution of asphalt aging, initially considering it as physical hardening and progressively ecognizing it as a complex phenomenon having repercussions on asphalt durability and physical-chemical properties. This document aims to be a guide for understanding future investigations for developing new types and mixtures of asphalt having improved properties.

  12. High-frequency behavior of FeN thin films fabricated by using reactive sputtering

    Science.gov (United States)

    Hwang, Tae-Jong; Lee, Joonsik; Kim, Ki Hyeon; Kim, Dong Ho

    2016-08-01

    We used ferromagnetic resonance (FMR) and its relationship with the static magnetic properties to investigate the high-frequency behavior of FeN thin films prepared by using reactive sputtering. The FMR was observed in the frequency range from 2 to 18 GHz in the FeN films fabricated at a proper nitrogen flow rate (NFR). In those FeN thin films, a decrease in the saturation magnetization and a corresponding decrease of the FMR frequency were observed as the NFR was increased during the deposition. The external field dependences of the FMR frequencies fit the Kittel formula well, and the Landé g-factors determined from the fit were found to be very close to the free electron value. The high-field damping parameters were almost insensitive to the NFR. However, the lowfield damping parameters exhibited a high sensitivity to the NFR very similar to the dependence of the hard-axis coercivity on the NFR, suggesting that extrinsic material properties, such as impurities and defect structures, could be important in deciding the low-field damping behavior.

  13. El concepto de fenómeno en el joven Heidegger

    Directory of Open Access Journals (Sweden)

    Francisco De Lara

    2008-01-01

    Full Text Available El presente trabajo es una discusión del concepto de fenómeno tal y como éste se encuentra determinado en la filosofía del joven Heidegger. Con ella se pretende ir a la base que permite dilucidar en qué sentido hace éste fenomenología o, en otras palabras, qué idea de filosofía se encuentra expresada bajo el título de hermenéutica fenomenológica. Al hilo de la lectura del concepto de fenómeno como concepto filosófico, esto es, como indicación formal, nos preguntaremos: 1 cómo se toma en consideración lo investigado fenomenológicamente; 2 cómo debe comparecer lo así investigado y 3 si, en efecto, el concepto de fenómeno funciona siempre en Heidegger como una indicación formal o si no puede constatarse en él una cierta ambigüedad.

  14. Ácidos fenólicos en paja de trigo. ¿Son éstos los compuestos fenólicos más importantes en la inhibición del crecimiento de las plantas?

    OpenAIRE

    Fidel René Díaz Serrano; Luis Felipe Ramírez Santoyo; Marcos R. Soto Hernández; Prometeo Sánchez García; Manuel Sandoval Villa; Gabriel Alcántar González; Roberto Quintero Lizaola

    2010-01-01

    Se identificaron los principales ácidos fenólicos presentes en paja de trigo por cromatografía líquida de alta resolución (CLAR), coincidiendo en general con los ácidos fenólicos reportados en la literatura científica como los principales compuestos alelopáticos presentes en la paja de trigo. Las concentraciones de estos ácidos fenólicos, cuantificadas en los extractos metanólicos por CLAR, fueron muy bajas (entre 0.17 % y 3.06 %) en relación con la cuantificación de fenólicos solubles totale...

  15. La religión como fenómeno antropológico – Elementos constitutivos del fenómeno religioso

    Directory of Open Access Journals (Sweden)

    Salustiano Alvarez Gómez

    2009-05-01

    Full Text Available El fenómeno religioso se hace presente en las culturas respondiendo a cuestiones humanas importantes. Forma la comprensión de la vida y elabora cosmologías. Desde sus intuiciones, se organiza elaborando los sentimientos de sagrado, realidades simbólicas, ritos, ética, etc. que construyen formas de relación social y comunitaria.Palabras clave: Religión; Teología; Filosofia; Antropología; Sociología; Cultura e moral.ABSTRACTThe religious phenomenon is present in cultures as a response to fundamental human questions. It shapes the understanding of life and elaborates cosmologies. With basis on its intuition, it organises itself elaborating the feelings of the sacred, symbolic realities, rites, ethics, and so on, which establish forms of social and communitarian relations.Key words: Religion; Theology; Philosophy; Anthropology; Sociology; Culture and morals.

  16. Stable Isotope Resolved Metabolomics Reveals the Role of Anabolic and Catabolic Processes in Glyphosate-Induced Amino Acid Accumulation in Amaranthus palmeri Biotypes.

    Science.gov (United States)

    Maroli, Amith; Nandula, Vijay; Duke, Stephen; Tharayil, Nishanth

    2016-09-21

    Biotic and abiotic stressors often result in the buildup of amino acid pools in plants, which serve as potential stress mitigators. However, the role of anabolic (de novo amino acid synthesis) versus catabolic (proteolytic) processes in contributing to free amino acid pools is less understood. Using stable isotope-resolved metabolomics (SIRM), we measured the de novo amino acid synthesis in glyphosate susceptible (S-) and resistant (R-) Amaranthus palmeri biotypes. In the S-biotype, glyphosate treatment at 0.4 kg ae/ha resulted in an increase in total amino acids, a proportional increase in both (14)N and (15)N amino acids, and a decrease in soluble proteins. This indicates a potential increase in de novo amino acid synthesis, coupled with a lower protein synthesis and a higher protein catabolism following glyphosate treatment in the S-biotype. Furthermore, the ratio of glutamine/glutamic acid (Gln/Glu) in the glyphosate-treated S- and R-biotypes indicated that the initial assimilation of inorganic nitrogen to organic forms is less affected by glyphosate. However, amino acid biosynthesis downstream of glutamine is disproportionately disrupted in the glyphosate treated S-biotype. It is thus concluded that the herbicide-induced amino acid abundance in the S-biotype is contributed by both protein catabolism and de novo synthesis of amino acids such as glutamine and asparagine.

  17. Mutagenesis of hetR reveals amino acids necessary for HetR function in the heterocystous cyanobacterium Anabaena sp. strain PCC 7120.

    Science.gov (United States)

    Risser, Douglas D; Callahan, Sean M

    2007-03-01

    HetR is the master regulator of heterocyst differentiation in the filamentous cyanobacterium Anabaena sp. strain PCC 7120. Genetic selection was used to identify 33 amino acid substitutions in HetR that reduced the proportion of cells undergoing heterocyst differentiation to less than 2%. Conservative substitutions in the wild-type HetR protein revealed three mutations that dramatically reduced the amount of heterocyst differentiation when the mutant allele was present in place of the wild-type allele on a replicating plasmid in a mutant lacking hetR on the chromosome. An H69Y substitution resulted in heterocyst formation among less than 0.1% of cells, and D17E and G36A substitutions resulted in a Het- phenotype, compared to heterocyst formation among approximately 25% of cells with the wild-type hetR under the same conditions. The D17E substitution prevented DNA binding activity exhibited by wild-type HetR in mobility shift assays, whereas G36A and H69Y substitutions had no affect on DNA binding. D17E, G36A, and H69Y substitutions also resulted in higher levels of the corresponding HetR protein than of the wild-type protein when each was expressed from an inducible promoter in a hetR deletion strain, suggesting an effect on HetR protein turnover. Surprisingly, C48A and S152A substitutions, which were previously reported to result in a Het- phenotype, were found to have no effect on heterocyst differentiation or patterning when the corresponding mutations were introduced into an otherwise wild-type genetic background in Anabaena sp. strain PCC 7120. The clustering of mutations that satisfied the positive selection near the amino terminus suggests an important role for this part of the protein in HetR function.

  18. Could Poor Fens BE More Sensitive than Bogs to Elevated N Deposition in the Oil Sands Region of Northern Alberta?

    Science.gov (United States)

    Wieder, R. K.; Vile, M. A.; Scott, K. D.

    2015-12-01

    Bogs and fens cover 29% of the 140,000 km2 Oil Sands Administrative Area (OSAA) in northern Alberta, a region characterized by quite low background N deposition (1-2 kg/ha/yr). However, development of the oil sands resource has led to increasing emission of nitrogen oxides, which are then returned to regional ecosystems as elevated atmospheric N deposition. Given the nutrient deficient nature of bogs and poor fens, elevated N deposition from oil sands development could potentially affect peatland ecosystem structure and function. To evaluate the ecosystem-level effects of N deposition, since 2011, we have experimentally applied N to a bog and a poor fen near Mariana Lakes, Alberta, located far enough from the OSAA to be unaffected by oil sands emissions. Treatments include simulated rainfall equivalent to N deposition of 0, 5, 10, 15, 20, and 25 kg/ha/yr, plus control plots receiving no added water (3 replicate plots per site per N treatment). Concentrations of NH4+-N, NO3- N, and DON at the top of the peatland water table did not increase with increasing N deposition, averaging 0.61, 0.09, and 1.07 mg/L, respectively, in the bog, and 0.53, 0.10, and 0.81 mg/L, respectively, in the poor fen. Ericaceous shrub abundance increased with increasing N deposition in both the bog and the poor fen, although plot-scale greenness (hand-held spectral measurement of the Normalized Difference Red Edge (NDRE) index) increased with N deposition in the poor fen, but not in the bog. Segmented regression indicated that in the poor fen, at N deposition above 14-16 kg/ha/yr, total microbial, bacterial, and fungal biomass in the top 5 cm of peat increased with N deposition, with no effect at lower N deposition. No effect of N deposition on microbial, bacterial, or fungal biomass was observed at 5-10 cm in the poor fen, or at either 0-5 or 5-10 cm in the bog. In the poor fen, microbial, bacterial, and fungal biomass increased with NDRE, but the effect was not significant in the bog

  19. Actividade antifúngica de extractos fenólicos do mel de Trás-os-Montes

    OpenAIRE

    Barros, Susana; Calhelha, Ricardo C.; Estevinho, Leticia M.

    2005-01-01

    O mel é considerado um produto alimentar benéfico e promotor de saúde, através da prevenção de doenças. Estas propriedades devem-se em parte a presença de compostos fenólicos (ácidos fenólicos e flavonóides) na sua composição.

  20. Integrated systems biology analysis of transcriptomes reveals candidate genes for acidity control in developing fruits of sweet orange (Citrus sinensis L. Osbeck

    Directory of Open Access Journals (Sweden)

    Dingquan eHuang

    2016-04-01

    Full Text Available Organic acids, such as citrate and malate, are important contributors for the sensory traits of fleshy fruits. Although their biosynthesis has been illustrated, regulatory mechanisms of acid accumulation remain to be dissected. To provide transcriptional architecture and identify candidate genes for citrate accumulation in fruits, we have selected for transcriptome analysis four varieties of sweet orange (Citrus sinensis L. Osbeck with varying fruit acidity, Succari (acidless, Bingtang (low acid, and Newhall and Xinhui (normal acid. Fruits of these varieties at 45 days post anthesis (DPA, which corresponds to Stage I (cell division, had similar acidity, but they displayed differential acid accumulation at 142 DPA (Stage II, cell expansion. Transcriptomes of fruits at 45 and 142 DPA were profiled using RNA sequencing and analyzed with three different algorithms (Pearson correlation, gene coexpression network and surrogate variable analysis. Our network analysis shows that the acid-correlated genes belong to three distinct network modules. Several of these candidate fruit acidity genes encode regulatory proteins involved in transport (such as AH10, degradation (such as APD2 and transcription (such as AIL6 and act as hubs in the citrate accumulation gene networks. Taken together, our integrated systems biology analysis has provided new insights into the fruit citrate accumulation gene network and led to the identification of candidate genes likely associated with the fruit acidity control.

  1. Seasonal Trace Gas Dynamics on Minerotrophic Fen Peatlands in NE-Germany

    Science.gov (United States)

    Giebels, Michael; Beyer, Madlen; Augustin, Jürgen; Minke, Merten; Juszczak, Radoszlav; Serba, Tomasz

    2010-05-01

    In Germany more than 99 % of fens have lost their carbon and nutrient sink function due to heavy drainage and agricultural land use especially during the last decades and thus resulted in compression and heavy peat loss (CHARMAN 2002; JOOSTEN & CLARKE 2002; SUCCOW & JOOSTEN 2001; AUGUSTIN et al. 1996; KUNTZE 1993). Therefore fen peatlands play an important part (4-5 %) in the national anthropogenic trace gas budget. But only a small part of drained and agricultural used fens in NE Germany can be restored. Knowledge of the influence of land use to trace gas exchange is important for mitigation of the climate impact of the anthropogenic peatland use. We study carbon exchanges of several fen peatland use areas between soil and atmosphere at different sites in NE-Germany. Our research covers peatlands of supposed strongly climate forcing land use (cornfield and intensive pasture) and of probably less forcing, alternative types (meadow and extensive pasture) as well as rewetted (formerly drained) areas and near-natural sites like a low-degraded fen and a wetted alder woodland. We measured trace gas fluxes with manual and automatic chambers in periodic routines since spring 2007. The used chamber technique bases on DROESLER (2005). In total we now do research at 22 sites situated in 5 different locations covering agricultural, varying states of rewetted and near-natural treatments. We present results of at least 2 years of measurements and show significant differences in their annual trace gas balances depending on the genesis of the observed sites and the seasonal dynamics. Crosswise comparison of different site treatments combined with the seasonal environmental observations give good hints for the identification of main flux driving parameters. That is that a reduced intensity in land use as a supposed mitigating treatment did not show the expected effect, though a normal meadow treatment surprisingly resulted in the lowest balances in both years. For implementing a

  2. Seasonal Carbon Dynamics on Selected Fen Peatland Sites in NE-Germany

    Science.gov (United States)

    Giebels, Michael; Beyer, Madlen; Augustin, Jürgen; Minke, Merten; Juszczak, Radoszlav; Serba, Tomasz

    2010-05-01

    In Germany more than 99 % of fens have lost their carbon and nutrient sink function due to heavy drainage and agricultural land use especially during the last decades and thus resulted in compression and heavy peat loss (CHARMAN 2002; JOOSTEN & CLARKE 2002; SUCCOW & JOOSTEN 2001; AUGUSTIN et al. 1996; KUNTZE 1993). Therefore fen peatlands play an important part (4-5 %) in the national anthropogenic trace gas budget. But only a small part of drained and agricultural used fens in NE Germany can be restored. Knowledge of the influence of land use to trace gas exchange is important for mitigation of the climate impact of the anthropogenic peatland use. We study carbon exchanges of several fen peatland use areas between soil and atmosphere at different sites in NE-Germany. Our research covers peatlands of supposed strongly climate forcing land use (cornfield and intensive pasture) and of probably less forcing, alternative types (meadow and extensive pasture) as well as rewetted (formerly drained) areas and near-natural sites like a low-degraded fen and a wetted alder woodland. We measured trace gas fluxes with manual and automatic chambers in periodic routines since spring 2007. The used chamber technique bases on DROESLER (2005). In total we now do research at 22 sites situated in 5 different locations covering agricultural, varying states of rewetted and near-natural treatments. We present results of at least 2 years of measurements and show significant differences in their annual carbon balances depending on the genesis of the observed sites and the seasonal dynamics. Crosswise comparison of different site treatments combined with the seasonal environmental observations give good hints for the identification of main flux driving parameters. That is that a reduced intensity in land use as a supposed mitigating treatment did not show the expected effect, though a normal meadow treatment surprisingly resulted in the lowest CO2 balances in both years. For implementing a

  3. Evaluation on the Efficiency of Subsurface Drainage in Chiu-Fen Landslide at Northern Taiwan

    Science.gov (United States)

    Ying, L. Y.; Lin, D. G.

    2015-12-01

    For administrative district, the Chiu-Fen landslide is situated at northern Taiwan and comes within the jurisdiction of Ruei-Fang district, New Taipei City Government. Chiu-Fen village is a famous spot for sightseeing and tourism in Southeast Asia. In the last decade, for economic purpose, a vast area of slope land in Chiu-Fen area was reclaimed into business and commercial districts. However, due to the complicated geological and hydrological conditions, improper reclamation, and lack of appropriate soil and water conservation facilities, large scale landslides are frequently triggered by typhoon rainfall and causes damages to the transportation and residential building in the community. As a consequence, the government initiated a comprehensive field investigations and remediation plans to stabilize the landslide from 1997 and the remediation works were concentrated on subsurface drainages, namely the application of drainage well (a vertical shaft with multi-level horizontal drainage boreholes). To investigate the efficiency of drainage wells on the landslide, the A1-profile in the landslide which covers the drainage wells W2 and W4 was selected for a series of rainfall seepage and slope stability analyses. In addition, a 48-hrs design rainfall with return period of 25, 50 and 100 years based on the local meteorological data bank was adopted for the analyses. The numerical results indicate the factor safety FS of the three potential sliding surfaces within A1-profile are constantly keeping greater than one (FS > 1.0) and without decreasing with the elapsed time during rainfall. This implies that the subsurface drainage works can drain off the infiltrated rainwater from a high intensity and long duration rainfall and preserve the slope stability of landslides from deterioration. Finally, the efficiency of the drainage wells can be evaluated quantitatively in terms of the time-dependent factor of safety and the pore water pressure distribution on several potential

  4. La implementación: un fenómeno organizativo multidimensional

    OpenAIRE

    Rivera Camino, Jaime

    1995-01-01

    Ante la creciente importancia del tema implementación para las disciplinas que estudian la empresa, este artículo persigue dos objetivos: resumir el estado actual de la literatura sobre el tema y presentar una definición que toma en consideración las diferentes tendencias y críticas en la implementación de estrategias competitivas. Esta definición integra varias disciplinas y permite concebir la implementación como un fenómeno multidimensional, el cual está formado por diversos niveles de agr...

  5. Pensamento, fenômeno experimental e experimento na proposta pragmaticista

    Directory of Open Access Journals (Sweden)

    Lauro Frederico Barbosa da Silveira

    1984-01-01

    Full Text Available O Pragmaticismo de Charles Sanders Peirce, como teoria geral da concepção, e uma teoria do signo e uma teoria do pensamento. Limitando-se à consideração do "teor racional" dos símbolos, o pragmaticismo procura estabelecer o tipo de causação atribuível ao pensamento: uma causação eficiente centralizada na percepção e no experimento e uma causação final que determina um hábito racional de conduta diante da classe geral de fenômenos experimentais representada no conceito.

  6. Turismo religioso: fenómeno social y económico

    OpenAIRE

    Sandra Maribel Tobón Perilla; Natalia Tobón Perilla

    2013-01-01

    El turismo religioso, como fenómeno social y económico, ha cobrado interés entre académicos y empresarios por las dinámicas que ha generado en las comunidades receptoras de visitantes. Para los primeros, el interés radica en el estudio de las motivaciones, intereses y necesidades espirituales o culturales que parecen haber despertado los centros religiosos; para los segundos, el impacto económico y las oportunidades de rentas adicionales que generan los visitantes, creando nuevas oportunidade...

  7. Aproximaci??n conceptual al fen??meno tur??stico en la actualidad

    OpenAIRE

    2004-01-01

    En el presente texto se recogen una serie de conceptos b??sicos, que es preciso tener en cuenta a la hora de emprender el estudio en profundidad de la actividad tur??stica, dentro de un contexto concreto. Est?? estructurado en seis apartados: tras la pertinente introducci??n, apuntamos algunas rese??as hist??ricas sobre el origen de la pr??ctica tur??stica, a continuaci??n se??alamos una serie de conceptos y tipolog??as elaboradas para la mejor comprensi??n del fen??meno, los elementos que co...

  8. Fenômeno de Lúcio fatal: relato de caso de autópsia

    OpenAIRE

    2012-01-01

    A Hanseníase de Lúcio e Alvarado, considerada a forma mais anérgica do espectro imunológico hansênico, caracteriza-se por espessamento e infiltração difusa, com alopecia difusa e total, associado a comprometimento sistêmico importante.Nessepolo da doença, os bacilos são numerosos em todos os tecidos. A alta carga bacilar no endotélio e o desenvolvimento de vasculite leucocitoclástica de pequenos e médiosvasos resultam em extensas áreas necrótico-ulcerativas, denominada fenômeno de Lúcio. Apre...

  9. Teor de fenólicos totais e atividade antioxidante das sementes da Carpotroche brasiliensis (Raddi)

    OpenAIRE

    2012-01-01

    p. 170-176 Introdução: A Carpotroche brasiliensis é uma árvore nativa brasileira, utilizada na medicina popular. Objetivo: avaliar a qualidade nutricional, fatores antinutricionais, teor de compostos fenólicos e determinar atividade antioxidante das sementes da planta. Metodologia: As sementes foram divididas em amostra natural (CB) e liofilizada (CBL). A composição centesimal e teor de ácido oxálico foram realizados em triplicata, segundo normas do Instituto Adolfo Lutz. O ácido ...

  10. Prevención de la violencia: El fenómeno Bullying

    OpenAIRE

    Alonso Pérez, Arantxa

    2014-01-01

    La finalidad de este trabajo es indagar y profundizar en el fenómeno bullying para posteriormente poder prevenir éste en las aulas de Educación Primaria a través de un programa aplicado en tercer ciclo. Se inicia con el estudio de las características principales del bullying, dando importancia a los agentes que participan. En segundo lugar, se enmarca el acoso entre iguales en la sociedad actual, es decir, se analiza cuáles son las características de nuestra sociedad que propician el surgimie...

  11. estudo do fenómeno em jovens estudantes do Ensino Secundário

    OpenAIRE

    Fonseca, Patrícia Marques

    2015-01-01

    Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para a obtenção do grau de Mestre em Psicologia Jurídica A presente investigação debruça-se sobre o estudo do bullying, cujos desenvolvimentos se têm dado não só de uma forma mais direta nas escolas, mas também através do uso das novas tecnologias, numa modalidade que se chama cyberbullying. Para isso, pretendeu-se analisar o fenómeno de bullying, nas duas modalidades presencial e virtual (cyberbullying), capt...

  12. "Linda de morrer": a anorexia como fenômeno sócio-cultural

    OpenAIRE

    Erika Ribeiro Conde

    2007-01-01

    O objetivo deste trabalho foi estudar a anorexia como um fenômeno sóciocultural, analisando a própria definição e tratamento desta patologia pela Medicina, explorando-lhe a perspectiva genealógica, compreendendo o valor social da alimentação e a relação que a anoréxica desenvolve com a dieta alimentar. Utilizouse dos conceitos de sociedade do espetáculo, cultura do narcisismo e das teorias de gênero como ferramentas teóricas capazes de compreender o valor da imagem corporal como fator prop...

  13. Cruzando fronteras: los fenómenos transpositivos de Juan Moreira. Novela, teatro y cine

    Directory of Open Access Journals (Sweden)

    Lía Sabrina Noguera

    2015-12-01

    Full Text Available En este artículo nos proponemos analizar la transposición de Juan Moreira en la literatura, el drama y, especialmente, en el cine argentino a partir de la versión que Leonardo Favio realizó en 1972. Nuestro objetivo es dar cuenta de las variantes de significación que se producen de un texto a otro, no solo en lo referente a lo propio del fenómeno transpositivo sino, y en especial, al modo en el que el contexto de producción resignifica los materiales discursivos y propone nuevos mitos sobre este héroe popular.

  14. Application of protein-phenolic based coating on tomatoes (Lycopersicum esculentum Aplicação de coberturas proteicas e fenólicas em tomates (Lycopersicum esculentum

    Directory of Open Access Journals (Sweden)

    Eliane Pereira Cipolatti

    2012-09-01

    Full Text Available The aim of this study was to investigate the use of protein-phenolic based coating made from fermented rice bran on cherry tomatoes (Lycopersicum esculentum. Tests were performed with glycerol 3% (v/v, glycerol with protein-phenolic rice bran extract (5%, glycerol with protein-phenolic extract after 96 hours of fermentation (5%, and a control (without coating. The coated cherry tomatoes were kept at room temperature for 28 days. Mass loss, pH and acidity, total soluble solids, and carotenoids were determined every 96 hours. The coating made from the biomass extract reduced the carotenoid and acidity levels in the fruits studied by 17 and 21.1%, respectively, compared to the control. The coating proved an efficient barrier to water vapor with mass loss of 57% less than the control suggesting that it can be used as an alternative for vegetable tissue conservation.Este trabalho teve como objetivo estudar a utilização de películas, à base de compostos proteicos e fenólicos provenientes de farelo de arroz fermentado, em tomates (Lycopersicum esculentum. Foram realizados testes com: glicerol 3% (v/v; glicerol com extrato fenólico e proteico do farelo de arroz (5%; glicerol com extrato fenólico e proteico da biomassa gerada em 96 hours (5%, e um controle (sem a película. Os tomates revestidos foram mantidos à temperatura ambiente durante 28 dias, sendo determinados, a cada 96 horas, os seguintes aspectos: a perda de massa, o pH e a acidez, os sólidos solúveis totais e os carotenoides. A película elaborada com os extratos da biomassa reduziu os níveis de carotenoides e acidez dos frutos estudados em 17 e 21,1%, respectivamente, em relação ao controle. A película também foi eficiente como barreira ao vapor de água; assim, com perda de massa 57% inferior à do controle, sugere-se que esta poderá ser utilizada como alternativa para conservação desse tecido vegetal.

  15. In Silico and Wet Lab Studies Reveal the Cholesterol Lowering Efficacy of Lauric Acid, a Medium Chain Fat of Coconut Oil.

    Science.gov (United States)

    Lekshmi Sheela, Devi; Nazeem, Puthiyaveetil Abdulla; Narayanankutty, Arunaksharan; Manalil, Jeksy Jos; Raghavamenon, Achuthan C

    2016-12-01

    The coconut oil (CO) contains 91 % of saturated fatty acids in which 72 % are medium chain fatty acids (MCFAs) like lauric, capric and caprylic acids. In contrast to animal fat, coconut oil has no cholesterol. Despite this fact, CO is sidelined among other vegetable oils due to the health hazards attributed to the saturated fatty acids. Though various medicinal effects of CO have been reported including the hypolipidemic activity, people are still confused in the consumption of this natural oil. In silico analyses and wet lab experiments have been carried out to identify the hypolipidemic properties of MCFAs and phenolic acids in CO by using different protein targets involved in cholesterol synthesis. The molecular docking studies were carried out using CDOCKER protocol in Accelery's Discovery Studio, by taking different proteins like HMG- CoA reductase and cholesterol esterase as targets and the different phytocompounds in coconut as ligands. Molecular docking highlighted the potential of lauric acid in inhibiting the protein targets involved in hyperlipidemics. Further, validation of in silico results was carried out through in vivo studies. The activity of key enzymes HMG- CoA reductase and lipoprotein lipase were found reduced in animals fed with lauric acid and CO.

  16. Genetic analysis of two OsLpa1-like genes in Arabidopsis reveals that only one is required for wild-type seed phytic acid levels

    Science.gov (United States)

    Phytic acid (inositol-1,2,3,4,5,6-hexakisphosphate or InsP6) is the primary storage form of phosphorus in plant seeds. The rice OsLpa1 encodes a novel protein required for wild-type levels of seed InsP6 and was identified from a low phytic acid (lpa) mutant exhibiting a 45-50% reduction in seed InsP...

  17. Reduction of Coercivity of Fe-N Soft Magnetic Film by Heat Treatment

    Institute of Scientific and Technical Information of China (English)

    Dan LI; Yousong GU; Xiangrong CHANG; Fushen LI; Lijie QIAO; Zhongzhuo TIAN

    2003-01-01

    200 nm thick Fe-N magnetic thin films were deposited on glass substrates by RF sputtering. The as-deposited films havehigh saturation magnetization but their coercivity is also higher than what is needed Therefore it is very important to reducecoercivity. The samples were vacuum annealed at 250℃ under 12000 A/m magnetic field. When the N content was in therange of 5~7 at. pct, the thin films consisted of α′ + α″ after heat treatment and had excellent soft magnetic properties of4rMs=2.4 T, HC <80 A/m. However, the thickness of a recording head was 2μm, andHc increased as thickness increased.In order to reduce the Hc, the sputtering power was raised from 200 W to 1000 W to reduce the grain size. 2μm Fe-N thinfilms were vacuum annealed under the same condition, when the N content was in the range of 5.9~8.5 at. pct, the thin filmskept its excellent magnetic properties of 4πMs=2.2 T, HC <80 A/m. The properties of the films meet the need of a recordinghead material used in the dual-element GMR/inductive heads.

  18. The Role of Sedges in Methane Production and Emission From a Temperate Fen

    Science.gov (United States)

    Noyce, G. L.; Szarkowski, E. R.; Bubier, J. L.; Varner, R. K.

    2008-12-01

    Northern peatlands are the largest single natural source of atmospheric methane (CH4) and thus any changes in these fluxes could have global consequences. Positive correlations have been observed between sedge biomass and high CH4 emissions from peatlands. We examined the effect that Carex rostrata has on methane production and transport in Sallie's Fen, Barrington, NH. During the summer of 2008, CH4 fluxes, pore-water CH4 concentrations, and C. rostrata biomass, along with temperature, net ecosystem CO2 exchange (NEE), and water table depth, were measured from both clipped and unclipped plots. In clipped plots, all C. rostrata were clipped below the peat surface and then sealed with petroleum jelly and plastic bags. Unclipped plots were left undisturbed. We observed a strong positive correlation between C. rostrata biomass and CH4 fluxes. Initial findings suggest that sedges have a strong effect on gas transport. The average 18 cm (C. rostrata rooting depth) pore water CH4 concentrations in the clipped plots (6141 ppm CH4) were significantly higher (p<0.001) than in the unclipped plots (3912 ppm CH4). The past 20 years of data at Sallie's Fen also show that plots with more C. rostrata have higher mid-season CH4 fluxes, on average, than shrub-dominated plots. Depth to water table, however, may be a stronger control on CH4 fluxes than vegetation.

  19. Environmental factors controlling fluxes of dimethyl sulfide in a New Hampshire fen

    Science.gov (United States)

    Demello, William Zamboni; Hines, Mark E.

    1992-01-01

    The major environmental factors controlling fluxes of dimethyl sulfide (DMS) in a Sphagnum-dominated peatland were investigated in a poor fen in New Hampshire. DMS emissions from the surface of the peatland varied greatly over 24 hours and seasonally. Maximum DMS emissions occurred in summer with minima in the late fall. Temperature was the major environmental factor controlling these variabilities. There was also some evidence that the changes in water table height might have contributed to the seasonable variability in DMS emission. The influence of the water table was greater during periods of elevated temperature. DMS and MSH were the most abundant dissolved volatile sulfur compound (VSC) in the surface of the water table. Concentrations of dissolved VSC's varied with time and space throughout the fen. Dissolved MDS, MSH, and OCS in the surface of the water table were supersaturated with respect to their concentrations in the atmosphere suggesting that the peat surface was a source of VSC's in the peatland. VCS in peatlands seemed to be produced primarily by microbial processes in the anoxic surface layers of the peat rich in organic matter and inorganic sulfide. Sphagnum mosses were not a direct source of VSC's. However, they increased transport of DMS from the peat surface to the atmosphere.

  20. Gravidez na adolescência: um olhar sobre um fenômeno complexo

    Directory of Open Access Journals (Sweden)

    Ana Cristina Garcia Dias

    2010-04-01

    Full Text Available O presente trabalho apresenta uma revisão seletiva e não sistemática da literatura a respeito do fenômeno da gestação na adolescência. Três eixos temáticos orientam a organização do trabalho: (a Riscos e problemas associados à gestação na adolescência; (b Fatores precursores relacionados à gravidez na adolescência; e (c Fatores sócio-culturais associados ao desejo de ser mãe na adolescência. Entre as conclusões, destaca-se que a gravidez na adolescência é uma experiência que pode ter consequências tanto negativas quanto positivas para os adolescentes. Além disso, o fenômeno evidencia a necessidade de intervenções voltadas à saúde sexual e reprodutiva dos adolescentes.

  1. A rainha sensual - uma análise do fenômeno Xuxa

    Directory of Open Access Journals (Sweden)

    Jupy Júnior

    2001-02-01

    Full Text Available

    Este artigo teve como origem a monografia de graduação do curso de Comunicação Social, habilitação jornalismo, da Universidade Federal Fluminense, orientada pelo professor doutor Luís Carlos Lopes,  tendo sido apresentada em abril de 2000. A intenção é criar uma discussão a respeito dos principais mecanismos sociais, econômicos, políticos e comunicacionais que tornam possíveis fenômenos de massa como a apresentadora Xuxa Meneghel. Este trabalho tenciona exibir uma persona midiática brasileira de forte apelo junto ao público por um ponto de vista analítico. Também tenciona levantar alguns aspectos que auxiliem em uma discussão mais profunda a respeito de outros fenômenos, bastante difundidos pela televisão – principalmente -, e de que maneira isto afeta a vida das pessoas e o imaginário coletivo brasileiro.

  2. O fenômeno psicossomático no rastro da letra

    Directory of Open Access Journals (Sweden)

    Roseane Freitas Nicolau

    2012-04-01

    Full Text Available Este artigo reflete uma preocupação clínica relativa à operação analítica junto aos fenômenos psicossomáticos. Fazendo-se um estudo das concepções lacanianas sobre o fenômeno psicossomático, nos detivemos nas proposições sobre a escrita, tomando-a na dimensão da escrita no corpo, a qual é uma dimensão distinta do registro do significante, para discutir a possibilidade de uma leitura nas entrelinhas da letra, na direção do tratamento. A relação entre letra e significante é destacada para pensar a passagem do gozo ao inconsciente, ou seja, do real ao simbólico, no manejo possível do gozo, segundo a lógica da quantificação, esperando que uma escrita do gozo possa operar. A ideia de que a escrita do corpo pressupõe efeito de sujeito, isto possibilita pensar o corpo marcado por cicatrizes, cuja operação é a leitura.

  3. Fenómenos que Organizan el Límite (Phenomena that Organize Limits

    Directory of Open Access Journals (Sweden)

    María Teresa Sánchez

    2007-03-01

    Full Text Available En este artículo se pone de manifiesto la presencia de los fenómenos de aproximación organizados por una definición de límite en el caso de las sucesiones de números reales y de las funciones reales de una variable real. La exposición incluye la caracterización de tales fenómenos, una descripción del análisis comparativo desarrollado en base a ellos entre dos definiciones formales de límite de sucesión y función, y una síntesis del estudio llevado a cabo sobre una muestra intencional de libros de texto de matemáticas.In this paper we show the presence of the phenomena of approximation organized by a definition of limit in the cases of the successions of real numbers and the real functions of one real variable. The exposition includes the characterization of such phenomena, a description of the comparative analysis, developed using them, between two formal definitions of limit of succession and function, and a synthesis of the study carried out on an intentional sample of mathematics textbooks.

  4. Real-Time Tracking of BODIPY-C12 Long-Chain Fatty Acid in Human Term Placenta Reveals Unique Lipid Dynamics in Cytotrophoblast Cells.

    Directory of Open Access Journals (Sweden)

    Kevin Kolahi

    Full Text Available While the human placenta must provide selected long-chain fatty acids to support the developing fetal brain, little is known about the mechanisms underlying the transport process. We tracked the movement of the fluorescently labeled long-chain fatty acid analogue, BODIPY-C12, across the cell layers of living explants of human term placenta. Although all layers took up the fatty acid, rapid esterification of long-chain fatty acids and incorporation into lipid droplets was exclusive to the inner layer cytotrophoblast cells rather than the expected outer syncytiotrophoblast layer. Cytotrophoblast is a progenitor cell layer previously relegated to a repair role. As isolated cytotrophoblasts differentiated into syncytialized cells in culture, they weakened their lipid processing capacity. Syncytializing cells suppress previously active genes that regulate fatty-acid uptake (SLC27A2/FATP2, FABP4, ACSL5 and lipid metabolism (GPAT3, LPCAT3. We speculate that cytotrophoblast performs a previously unrecognized role in regulating placental fatty acid uptake and metabolism.

  5. RNA-Seq-based transcriptomic and metabolomic analysis reveal stress responses and programmed cell death induced by acetic acid in Saccharomyces cerevisiae

    Science.gov (United States)

    Dong, Yachen; Hu, Jingjin; Fan, Linlin; Chen, Qihe

    2017-01-01

    As a typical harmful inhibitor in cellulosic hydrolyzates, acetic acid not only hinders bioethanol production, but also induces cell death in Saccharomyces cerevisiae. Herein, we conducted both transcriptomic and metabolomic analyses to investigate the global responses under acetic acid stress at different stages. There were 295 up-regulated and 427 down-regulated genes identified at more than two time points during acetic acid treatment (150 mM, pH 3.0). These differentially expressed genes (DEGs) were mainly involved in intracellular homeostasis, central metabolic pathway, transcription regulation, protein folding and stabilization, ubiquitin-dependent protein catabolic process, vesicle-mediated transport, protein synthesis, MAPK signaling pathways, cell cycle, programmed cell death, etc. The interaction network of all identified DEGs was constructed to speculate the potential regulatory genes and dominant pathways in response to acetic acid. The transcriptional changes were confirmed by metabolic profiles and phenotypic analysis. Acetic acid resulted in severe acidification in both cytosol and mitochondria, which was different from the effect of extracellular pH. Additionally, the imbalance of intracellular acetylation was shown to aggravate cell death under this stress. Overall, this work provides a novel and comprehensive understanding of stress responses and programmed cell death induced by acetic acid in yeast. PMID:28209995

  6. Compostos fenólicos e capacidade antioxidante em frutos de tomateiros mutantes fotomorfogenéticos

    Directory of Open Access Journals (Sweden)

    Tiago Dias

    2015-05-01

    Full Text Available Compostos fenólicos e capacidade antioxidante são mecanismos de defesa das plantas aos danos do estresse oxidativo. Os compostos fenólicos são sintetizados pela via dos fenilpropanoides, cuja enzima chave, fenilalanina amônia liase, é influenciada pela luz e ação de fotorreceptores, como o fitocromo. O objetivo do presente trabalho é avaliar a concentração de compostos fenólicos e a capacidade antioxidante de frutos de microtomateiro selvagem, cultivar "Micro-Tom" (MT, e seus mutantes fotomorfogenéticos high pigment 1 (hp1, super-responsivo a eventos mediados por luz e aurea (au, deficiente quantitativo em fitocromos. Vinte frutos maduros de cada genótipo (MT, hp1 e au foram utilizados para as análises, realizadas em triplicata. Para quantificação dos compostos fenólicos totais, foi utilizado o método de Folin-Ciocalteu e a capacidade antioxidante foi realizada pelos métodos Ferric Reducing Antioxidant Power (FRAP e 2,2-diphenyl-1-picrylhydrazyl (DPPH. Os frutos do mutante hp1 apresentaram maiores conteúdos de compostos fenólicos totais e também maior capacidade antioxidante em relação à cultivar selvagem ("MT" e ao mutante au, o qual não diferiu significativamente da cultivar "MT".

  7. Overexpression of human fatty acid transport protein 2/very long chain acyl-CoA synthetase 1 (FATP2/Acsvl1) reveals distinct patterns of trafficking of exogenous fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Melton, Elaina M. [Department of Biochemistry, University of Nebraska, Lincoln, NE (United States); Center for Cardiovascular Sciences, Albany Medical College, Albany, NY (United States); Cerny, Ronald L. [Department of Chemistry, University of Nebraska, Lincoln, NE (United States); DiRusso, Concetta C. [Department of Biochemistry, University of Nebraska, Lincoln, NE (United States); Black, Paul N., E-mail: pblack2@unl.edu [Department of Biochemistry, University of Nebraska, Lincoln, NE (United States)

    2013-11-01

    Highlights: •Roles of FATP2 in fatty acid transport/activation contribute to lipid homeostasis. •Use of 13C- and D-labeled fatty acids provide novel insights into FATP2 function. •FATP2-dependent trafficking of FA into phospholipids results in distinctive profiles. •FATP2 functions in the transport and activation pathways for exogenous fatty acids. -- Abstract: In mammals, the fatty acid transport proteins (FATP1 through FATP6) are members of a highly conserved family of proteins, which function in fatty acid transport proceeding through vectorial acylation and in the activation of very long chain fatty acids, branched chain fatty acids and secondary bile acids. FATP1, 2 and 4, for example directly function in fatty acid transport and very long chain fatty acids activation while FATP5 does not function in fatty acid transport but activates secondary bile acids. In the present work, we have used stable isotopically labeled fatty acids differing in carbon length and saturation in cells expressing FATP2 to gain further insights into how this protein functions in fatty acid transport and intracellular fatty acid trafficking. Our previous studies showed the expression of FATP2 modestly increased C16:0-CoA and C20:4-CoA and significantly increased C18:3-CoA and C22:6-CoA after 4 h. The increases in C16:0-CoA and C18:3-CoA suggest FATP2 must necessarily partner with a long chain acyl CoA synthetase (Acsl) to generate C16:0-CoA and C18:3-CoA through vectorial acylation. The very long chain acyl CoA synthetase activity of FATP2 is consistent in the generation of C20:4-CoA and C22:6-CoA coincident with transport from their respective exogenous fatty acids. The trafficking of exogenous fatty acids into phosphatidic acid (PA) and into the major classes of phospholipids (phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidyserine (PS)) resulted in distinctive profiles, which changed with the expression of FATP2. The

  8. Overexpression of human fatty acid transport protein 2/very long chain acyl-CoA synthetase 1 (FATP2/Acsvl1) reveals distinct patterns of trafficking of exogenous fatty acids.

    Science.gov (United States)

    Melton, Elaina M; Cerny, Ronald L; DiRusso, Concetta C; Black, Paul N

    2013-11-01

    In mammals, the fatty acid transport proteins (FATP1 through FATP6) are members of a highly conserved family of proteins, which function in fatty acid transport proceeding through vectorial acylation and in the activation of very long chain fatty acids, branched chain fatty acids and secondary bile acids. FATP1, 2 and 4, for example directly function in fatty acid transport and very long chain fatty acids activation while FATP5 does not function in fatty acid transport but activates secondary bile acids. In the present work, we have used stable isotopically labeled fatty acids differing in carbon length and saturation in cells expressing FATP2 to gain further insights into how this protein functions in fatty acid transport and intracellular fatty acid trafficking. Our previous studies showed the expression of FATP2 modestly increased C16:0-CoA and C20:4-CoA and significantly increased C18:3-CoA and C22:6-CoA after 4h. The increases in C16:0-CoA and C18:3-CoA suggest FATP2 must necessarily partner with a long chain acyl CoA synthetase (Acsl) to generate C16:0-CoA and C18:3-CoA through vectorial acylation. The very long chain acyl CoA synthetase activity of FATP2 is consistent in the generation of C20:4-CoA and C22:6-CoA coincident with transport from their respective exogenous fatty acids. The trafficking of exogenous fatty acids into phosphatidic acid (PA) and into the major classes of phospholipids (phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidyserine (PS)) resulted in distinctive profiles, which changed with the expression of FATP2. The trafficking of exogenous C16:0 and C22:6 into PA was significant where there was 6.9- and 5.3-fold increased incorporation, respectively, over the control; C18:3 and C20:4 also trended to increase in the PA pool while there were no changes for C18:1 and C18:2. The trafficking of C18:3 into PC and PI trended higher and approached significance. In the case of C20:4, expression of

  9. Estabelecimento de parâmetros reológicos na obtenção de compósitos carbono/fenólica

    OpenAIRE

    Edson C. Botelho; Scherbakoff,Natália; Mirabel C Rezende

    1999-01-01

    As resinas fenólicas têm sido utilizadas no processamento de compósitos carbono/carbono, produzindo um material intermediário conhecido como compósito carbono/fenólica. O presente trabalho mostra os resultados obtidos de análises reológicas, cromatográficas e por calorimetria exploratória diferencial (DSC) de duas amostras de resinas fenólicas tipo novolaca e uma resol, visando escolher a matéria-prima e os parâmetros mais adequados ao processamento de compósitos carbono/fenólica. Os resultad...

  10. Restoration of a Rich Fen by Top Soil Removal : Temporal and Spatial Responses among Vascular Plants, Bryophytes and Land Snails during 15 years

    OpenAIRE

    Evasdotter, Liselott

    2011-01-01

    Rich fens are calcareous and nutrient poor wetlands with a rich flora of orchids, sedges and mosses. As many as one hundred plant species are rich fen specialists. Many wetlands have been drained historically, and transformed to agricultural land or production forests. Today rich fens cover only 2-3% of the total mire area in Sweden. Rich fen is a rare and valuable habitat also from a European perspective and is protected in the Natura 2000-network. To increase and maintain the biodiversity a...

  11. Structure and magnetic properties of columnar Fe-N thin films deposited by direct current magnetron sputtering

    Institute of Scientific and Technical Information of China (English)

    JIA Hui; WANG Xin; PANG Shao-ping; ZHENG Wei-tao; LONG Bei-hong; LI Bo

    2009-01-01

    Columnar Fe-N thin films with thickness ranging from 30 to 150 nm were deposited by direct current magnetron sputtering using an Ar/N2 gas mixture (V(N2)/V(N2+Ar)=5%) on corning glass substrates. The structure, surface morphology and magnetic properties were investigated using X-ray diffractometry(XRD), scanning electron microscopy, atomic force microscopy, transmission electron microscopy(TEM) and superconducting quantum interference magnetometry. XRD investigation shows that Fe-N films exhibit amorphous-like structures; however, TEM measurements indicate the synthesis of mixture phases of α-Fe+ζ-Fe2N+ε-Fe3N in these films. The magnetic anisotropy and coercivity of Fe-N thin films exhibit strong dependence on the film growth behavior and surface morphology. With increasing the height of Fe-N films with column structures, the coercivity increases from 7.96 kA/m to 22.28 kA/m in the direction parallel to the film surface. In perpendicular direction the coercivity only increases slightly from 39.79 kA/m to 43.77 kA/m. However, the values of anisotropy field increase from 0.79×106 to 1.44×106 A/m, which is mainly attributed to the shape anisotropy of elongated columns due to the fact that the difference of magneto-crystalline anisotropy among these Fe-N films is small. The saturation magnetizations of Fe-N films vary with increasing film thickness from 23.5 to 85.1 A-m2/kg.

  12. The response of soil organic carbon of a rich fen peatland in interior Alaska to projected climate change

    Science.gov (United States)

    Fan, Zhaosheng; McGuire, Anthony David; Turetsky, Merritt R.; Harden, Jennifer W.; Waddington, James Michael; Kane, Evan S.

    2013-01-01

    It is important to understand the fate of carbon in boreal peatland soils in response to climate change because a substantial change in release of this carbon as CO2 and CH4 could influence the climate system. The goal of this research was to synthesize the results of a field water table manipulation experiment conducted in a boreal rich fen into a process-based model to understand how soil organic carbon (SOC) of the rich fen might respond to projected climate change. This model, the peatland version of the dynamic organic soil Terrestrial Ecosystem Model (peatland DOS-TEM), was calibrated with data collected during 2005–2011 from the control treatment of a boreal rich fen in the Alaska Peatland Experiment (APEX). The performance of the model was validated with the experimental data measured from the raised and lowered water-table treatments of APEX during the same period. The model was then applied to simulate future SOC dynamics of the rich fen control site under various CO2 emission scenarios. The results across these emissions scenarios suggest that the rate of SOC sequestration in the rich fen will increase between year 2012 and 2061 because the effects of warming increase heterotrophic respiration less than they increase carbon inputs via production. However, after 2061, the rate of SOC sequestration will be weakened and, as a result, the rich fen will likely become a carbon source to the atmosphere between 2062 and 2099. During this period, the effects of projected warming increase respiration so that it is greater than carbon inputs via production. Although changes in precipitation alone had relatively little effect on the dynamics of SOC, changes in precipitation did interact with warming to influence SOC dynamics for some climate scenarios.

  13. Highly expressed amino acid biosynthesis genes revealed by global gene expression analysis of Salmonella enterica serovar Enteritidis during growth in whole egg are not essential for this growth

    DEFF Research Database (Denmark)

    Jakočiūnė, Dzuiga; Herrero-Fresno, Ana; Jelsbak, Lotte;

    2016-01-01

    RNA was extracted from S. Enteritidis using a modified RNA-extraction protocol. Global gene expression during growth in whole egg was compared to growth in LB-medium using DNA array method. Twenty-six genes were significantly upregulated during growth in egg; these belonged to amino acid biosynthesis...

  14. High-Quality Draft Genome Sequence of Kallotenue papyrolyticum JKG1T Reveals Broad Heterotrophic Capacity Focused on Carbohydrate and Amino Acid Metabolism.

    Science.gov (United States)

    Hedlund, Brian P; Murugapiran, Senthil K; Huntemann, Marcel; Clum, Alicia; Pillay, Manoj; Palaniappan, Krishnaveni; Varghese, Neha; Mikhailova, Natalia; Stamatis, Dimitrios; Reddy, T B K; Ngan, Chew Yee; Daum, Chris; Duffy, Kecia; Shapiro, Nicole; Markowitz, Victor; Ivanova, Natalia; Kyrpides, Nikos; Williams, Amanda J; Cole, Jessica K; Dodsworth, Jeremy A; Woyke, Tanja

    2015-12-03

    The draft genome of Kallotenue papyrolyticum JKG1(T), a member of the order Kallotenuales, class Chloroflexia, consists of 4,475,263 bp in 4 contigs and encodes 4,010 predicted genes, 49 tRNA-encoding genes, and 3 rRNA operons. The genome is consistent with a heterotrophic lifestyle including catabolism of polysaccharides and amino acids.

  15. Highly expressed amino acid biosynthesis genes revealed by global gene expression analysis of Salmonella enterica serovar Enteritidis during growth in whole egg are not essential for this growth.

    Science.gov (United States)

    Jakočiūnė, Džiuginta; Herrero-Fresno, Ana; Jelsbak, Lotte; Olsen, John Elmerdahl

    2016-05-01

    Salmonella enterica serovar Enteritidis (S. Enteritidis) is the most common cause of egg borne salmonellosis in many parts of the world. This study analyzed gene expression of this bacterium during growth in whole egg, and whether highly expressed genes were essential for the growth. High quality RNA was extracted from S. Enteritidis using a modified RNA-extraction protocol. Global gene expression during growth in whole egg was compared to growth in LB-medium using DNA array method. Twenty-six genes were significantly upregulated during growth in egg; these belonged to amino acid biosynthesis, di/oligopeptide transport system, biotin synthesis, ferrous iron transport system, and type III secretion system. Significant downregulation of 15 genes related to formate hydrogenlyase (FHL) and trehalose metabolism was observed. The results suggested that S. Enteritidis is starved for amino-acids, biotin and iron when growing in egg. However, site specific mutation of amino acid biosynthesis genes asnA (17.3 fold upregulated), asnB (18.6 fold upregulated), asnA/asnB and, serA (12.0 fold upregulated) and gdhA (3.7 fold upregulated), did not result in growth attenuation, suggesting that biosynthesis using the enzymes encoded from these genes may represent the first choice for S. Enteritidis when growing in egg, but when absent, the bacterium could use alternative ways to obtain the amino acids.

  16. Decoding genome-wide GadEWX-transcriptional regulatory networks reveals multifaceted cellular responses to acid stress in Escherichia coli

    DEFF Research Database (Denmark)

    Seo, Sang Woo; Kim, Donghyuk; O'Brien, Edward J.;

    2015-01-01

    The regulators GadE, GadW and GadX (which we refer to as GadEWX) play a critical role in the transcriptional regulation of the glutamate-dependent acid resistance (GDAR) system in Escherichia coli K-12 MG1655. However, the genome-wide regulatory role of GadEWX is still unknown. Here we comprehens...

  17. Transcriptome sequencing revealed the transcriptional organization at ribosome-mediated attenuation sites in Corynebacterium glutamicum and identified a novel attenuator involved in aromatic amino acid biosynthesis.

    Science.gov (United States)

    Neshat, Armin; Mentz, Almut; Rückert, Christian; Kalinowski, Jörn

    2014-11-20

    The Gram-positive bacterium Corynebacterium glutamicum belongs to the order Corynebacteriales and is used as a producer of amino acids at industrial scales. Due to its economic importance, gene expression and particularly the regulation of amino acid biosynthesis has been investigated extensively. Applying the high-resolution technique of transcriptome sequencing (RNA-seq), recently a vast amount of data has been generated that was used to comprehensively analyze the C. glutamicum transcriptome. By analyzing RNA-seq data from a small RNA cDNA library of C. glutamicum, short transcripts in the known transcriptional attenuators sites of the trp operon, the ilvBNC operon and the leuA gene were verified. Furthermore, whole transcriptome RNA-seq data were used to elucidate the transcriptional organization of these three amino acid biosynthesis operons. In addition, we discovered and analyzed the novel attenuator aroR, located upstream of the aroF gene (cg1129). The DAHP synthase encoded by aroF catalyzes the first step in aromatic amino acid synthesis. The AroR leader peptide contains the amino acid sequence motif F-Y-F, indicating a regulatory effect by phenylalanine and tyrosine. Analysis by real-time RT-PCR suggests that the attenuator regulates the transcription of aroF in dependence of the cellular amount of tRNA loaded with phenylalanine when comparing a phenylalanine-auxotrophic C. glutamicum mutant fed with limiting and excess amounts of a phenylalanine-containing dipeptide. Additionally, the very interesting finding was made that all analyzed attenuators are leaderless transcripts.

  18. Algumas reflexões para estabelecer a cronologia do "fenômeno transexual" (1910-1995

    Directory of Open Access Journals (Sweden)

    Castel Pierre-Henri

    2001-01-01

    Full Text Available O "fenômeno transexual" (Benjamin é um indicador muito seguro das modificações históricas da percepção científica, mas também cultural e política da identidade sexual no século XX. Para apresentar uma cronologia e uma bibliografia escolhida desse fenômeno, este artigo propõe um fio condutor: a recusa sistemática das interpretações psicanalíticas do transexualismo pelos sexólogos, endocrinologistas e sociólogos que estudaram o problema.

  19. Algumas reflexões para estabelecer a cronologia do "fenômeno transexual" (1910-1995)

    OpenAIRE

    Pierre-Henri Castel

    2001-01-01

    O "fenômeno transexual" (Benjamin) é um indicador muito seguro das modificações históricas da percepção científica, mas também cultural e política da identidade sexual no século XX. Para apresentar uma cronologia e uma bibliografia escolhida desse fenômeno, este artigo propõe um fio condutor: a recusa sistemática das interpretações psicanalíticas do transexualismo pelos sexólogos, endocrinologistas e sociólogos que estudaram o problema.The "Transsexual Phenomenon" (Benjamin) is a reliable ind...

  20. Minor long-term effects of ultraviolet-B radiation on methane dynamics of a subarctic fen in Northern Finland

    DEFF Research Database (Denmark)

    Mörsky, Sami K.; Haapala, Jaana K.; Rinnan, Riikka;

    2012-01-01

    The effects of elevated ultraviolet-B (UVB) radiation on methane dynamics was studied in a natural fen in Northern Finland for three growing seasons (2003–2005). This is the first in situ study on the effects of elevated UV-B radiation on methane dynamics in a natural fen. The experimental setup....... The results emphasize the need for long-term field studies under moderately enhanced exposures to estimate whether the function and feedbacks of mire ecosystems change under increased UV-B radiation....

  1. Potencial de compostos fenólicos como antimicrobianos e/ou moduladores da resistência em Staphylococcus aureus

    OpenAIRE

    Silva, Helena Taina Diniz

    2015-01-01

    Os compostos fenólicos constituem uma das principais classes de metabólitos secundários de plantas, sintetizados para a defesa vegetal e adaptação ao estresse ambiental. Estão subdivididos em três grupos: ácidos fenólicos, flavonoides e taninos. Têm sido propostos como tendo uma variedade de efeitos biológicos na saúde humana e sobre microrganismos como S. aureus. Casos de infecções provocadas por cepas de S. aureus multi droga resistentes (MDR) têm aumentando ao longo dos anos...

  2. Exchange coupling and noncollinear magnetic states in Ni/Fen/Ni(1 0 0) multilayers

    Science.gov (United States)

    Malonda-Boungou, B. R.; Stojić, N.; Binggeli, N.; M'Passi-Mabiala, B.

    2015-01-01

    The Ni interlayer exchange coupling (IEC) and the atomic-scale magnetic configurations in fcc Ni /Fen /Ni (1 0 0) multilayers, with ultrathin Fe spacers, are investigated using first-principles density-functional theory including the noncollinear spin formalism. The trends with changing Fe thickness (n) between 3 and 5 monolayers (MLs) are examined. For n = 3 and 4 MLs, we find the ground state to display antiferromagnetic IEC between the Ni films, while for the 5-ML Fe spacer, the IEC changes into ferromagnetic. Upon reversal of the magnetization alignment, from antiparallel to parallel, between the Ni films with 3- and 4-ML thick Fe spacer, we find noncollinear magnetic configurations in the Fe layer as the lowest-energy states, which are related to the magnetic instability towards noncollinear solutions in bulk γ -Fe.

  3. Partitioning of habitat effects casts light on the decline of the fen orchid, Liparis loeselii

    DEFF Research Database (Denmark)

    Andersen, Dagmar Kappel; Ejrnæs, Rasmus; Minter, Martine Olesen

    2015-01-01

    Liparis loeselii is a rare and declining orchid species restricted to rich fens in the northern hemisphere. Suggested reasons for the decline are habitat destruction, eutrophication, altered hydrology and scrub encroachment after termination of traditional management such as grazing and hay making....... However, which parameters are most important is not well understood. We use data on vegetation and environmental parameters from extant, potential and historical L. loeselii habitats in Denmark to i) identify a relevant spatial scale for studying L. loeselii; 0.01 m2, 0.25 m2 and 78.5 m2 was tested, ii......) develop a habitat suitability model based on either Ellenberg indicator values or directly measured variables such as tissue nutrient concentrations and vegetation height, and iii) identify the primary reasons for the species decline. We found the largest spatial scale, 78.5 m2 to be superior...

  4. Fenómenos solares que afectan la atmósfera terrestre

    Science.gov (United States)

    Rovira, M.

    Se describen los principales fenómenos solares como fulguraciones, prominencias eruptivas, viento solar y eyecciones de masa coronal (CME) que tienen consecuencias en la atmósfera terrestre. En algunos casos el material es eyectado a velocidades superiores a los 900 km/seg y tarda menos de 48 horas en llegar a la Tierra. En general, estos CME no son peligrosos ya que el campo magnético terrestre actúa como protector siendo un aislante efectivo. Si el viento solar es muy intenso puede comprimir la magnetósfera y producir una tormenta geomagnética. En casos extremos, puede interferir la transmisión de potencia eléctrica, perturbar los satélites y producir auroras polares.

  5. Relations between vegetation and water level in alkaline fen ecosystems in Denmark

    DEFF Research Database (Denmark)

    Munch Johansen, Ole; Andersen, Dagmar Kappel; Ejrnæs, Rasmus

    2017-01-01

    and low and high water level periods, were calculated based on the water level time series. A complete plant species list was recorded in plots covering 78.5 m2 at each site. Community metrics such as total number of species and the number of bryophytes were generated from the species lists and Ellenberg...... Indicator scores of moisture, pH and nutrients were calculated for each site. The water level correlates with the number of typical fen species of vascular plants, whereas bryophytes are closer connected to the stable water level conditions provided by groundwater seepage. The water level variability...... is proved to be a significant limiting factor for species diversity in wetlands, which should be considered along with the fertility in order to access the habitat quality. The study provides new insight in the water level preferences for GWDTEs which is highly needed in the management and assessment...

  6. Climate change effects on lowland stream flood regimes and riparian rich fen vegetation communities in Denmark

    DEFF Research Database (Denmark)

    Thodsen, Hans; Baattrup-Pedersen, Annette; Andersen, Hans Estrup;

    2016-01-01

    to a hydrological model with the aim to predict climate driven changes in flooding regimes in lowland riparian areas. Our specific aims were to 1) predict effects of climate change on flood frequencies and magnitudes in riparian areas by using an ensemble of six climate models and 2) combine the obtained......There is growing awareness that an intensification of the hydrological cycle associated with climate change in many parts of the world will have profound implications for river ecosystem structure and functions. In the present study we link an ensemble of regional climate model projections...... predictions with the distribution of rich fen communities to explore whether these are likely to be subjected to increased flooding by a climate change induced increase in river runoff. We found that all regional climate models in the ensemble showed increases in mean annual runoff and that the increase...

  7. Hipertermia durante el fenómeno de El Niño, 1997-98

    OpenAIRE

    Miranda M., Jaime; Facultad de Medicina, Universidad Peruana Cayetano Heredia Lima, Perú.; Cabezas S, César; Instituto Nacional de Salud, Lima, Perú; Maguiña V., Ciro; Instituto de Medicina Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia. Lima, Perú.; Valdivia M., Juan; Facultad de Medicina, Universidad Peruana Cayetano Heredia. Lima, Perú.

    2003-01-01

    Objetivo: Describir el cuadro clínico y la evolución de los casos de síndrome febril presentados durante el fenómeno de “El Niño” de 1997-98, y presentar una revisión de la fisiopatología del cuadro de hipertermia. Material y métodos: Se realizó un estudio descriptivo longitudinal en la ciudad de Chimbote, Ancash. Se definió como caso de síndrome febril: niños menores de 5 años con fiebre refractaria al uso de antipiréticos sin foco aparente de infección. En el análisis posterior se considera...

  8. Hipertemia durante el fenómeno de el niño, 1997-98

    OpenAIRE

    Jaime Miranda M; César Cabezas S; Ciro Maguiña V; Juan Valdivia M

    2003-01-01

    Objetivo: Describir el cuadro clínico y la evolución de los casos de síndrome febril presentados durante el fenómeno de "El Niño" de 1997-98, y presentar una revisión de la fisiopatología del cuadro de hipertermia. Material y métodos: Se realizó un estudio descriptivo longitudinal en la ciudad de Chimbote, Ancash. Se definió como caso de síndrome febril: niños menores de 5 años con fiebre refractaria al uso de antipiréticos sin foco aparente de infección. En el análisis posterior se considera...

  9. Reconstruction of annual carbon dynamics and balance for an oligotrophic pine fen

    Energy Technology Data Exchange (ETDEWEB)

    Alm, J.; Silvola, J.; Aaltonen, H. [Joensuu Univ. (Finland). Dept. of Biology; Talanov, A.; Ikkonen, E. [Karelian Research Centre of Russian Academy of Sciences (Russian Federation). Inst. of Biology; Nykaenen, H.; Martikainen, P.J. [National Public Health Inst. Kuopio (Finland). Dept. of Environmental Microbiology

    1996-12-31

    Atmospheric carbon dioxide (CO{sub 2}) is bound by mire vegetation in photosynthesis during the growing season, and is re-released by respiration of plants, soil animals and microorganisms consuming dead organic matter. A small proportion of annual primary production may fall below the water table to anoxic conditions and thus escapes the oxidative decomposition. Also from anoxic peat, carbon is released with clear seasonal and spatial variation as methane (CH{sub 4}.). The rate of carbon accumulation in peat depends on the annual inbalance of plant production and litter decomposition. Exchange of CO{sub 2} and CH{sub 4} between peat, vegetation and the atmosphere thus reflects the dynamics of carbon flows in the ecosystem. Net ecosystem CO{sub 2} exchange (PN), total CO{sub 2} release (RTOT) and CH{sub 4} release (D) from different treeless surfaces of low-sedge Sphagnum papillosum pine fen was studied in eastern Finland. (8 refs.)

  10. Solute movement in drained fen peat: a field tracer study in a Somerset (UK) wetland

    Science.gov (United States)

    Baird, Andrew J.; Gaffney, Simon W.

    2000-10-01

    Little is known about solute transport in peats, despite the obvious importance of solute transport on eco-hydrological processes in both managed and natural peatlands. To address this lack of knowledge, we investigated solute transport processes in an agricultural fen peat using a conservative KBr tracer. The main aim of the study was to elucidate solute transport behaviour in general in this peat, with a more specific aim of investigating whether preferential or bypassing flow occurred. The tracer moved through the peat more rapidly than expected, and the pattern of movement showed clear evidence of plot-scale bypassing flow. The data also provide evidence that bypassing flow occurs in pores at smaller scales. The implications of this study for management of wetland pastures in the Somerset Moors in south-west England are discussed.

  11. El fenómeno erotic-grotesque nansensu en las obras de Edogawa Ranpo

    OpenAIRE

    Carrascosa Hitos, Laura Maria

    2016-01-01

    El principal objetivo de este trabajo es exponer los elementos del ero-guro nansensu en tres de las obras del escritor japonés Edogawa Ranpo: 'La silla humana', 'La oruga' y 'El demonio de la isla solitaria'. Con tal de facilitar la comprensión del lector, los análisis serán precedidos por una explicación sobre la historia del origen y el desarrollo de este fenómeno literario, además de la biografía y una breve introducción a la carrera del autor. Además, también se explicará el otro elemento...

  12. El fenómeno de la "edicionalización" y la prensa local

    Directory of Open Access Journals (Sweden)

    Dra. Antonia González Borjas

    2000-01-01

    Full Text Available El auge experimentado por la prensa local en los últimos años tiene como correlato el interés empresarial de los mass media por satisfacer demandas limitadas a zonas determinadas. Como consecuencia de ello, el periódico local se ha visto acompañado del fenómeno de la "edicionalización", proceso mediante el cual los medios de difusión nacional o regional han logrado un nuevo producto informativo para ciudades distintas con tan sólo cambiar parte de su paginación. Esta dialéctica lleva consigo un doble comportamiento mediático: el rol de contención por parte de las publicaciones locales, mientras que la prensa de ámbito mayor desarrolla el expansionismo informativo.

  13. Innovative wetland reclamation design case studies : the Suncor fen and pond 1 marsh

    Energy Technology Data Exchange (ETDEWEB)

    Daly, C.A. [Suncor Energy, Fort McMurray, AB (Canada); Price, J.; Rezanezhad, F. [Waterloo Univ., ON (Canada); Rochefort, L.; Graf, M. [Laval Univ., Quebec City, PQ (Canada); Russell, B. [BGC Engineering Inc., Calgary, AB (Canada)

    2010-07-01

    Suncor Energy Inc. is an energy company strategically focused in Canada's Athabasca oil sands region. The company has more than 40 years of experience in pioneering commercial development. This presentation discussed reclamation requirements for Suncor Energy. Reclamation objectives that were addressed in this presentation included operating approvals, biodiversity and meeting stakeholder expectations. Several photographs of reclaimed forest areas were shown along with 5 freshwater wetland types and wetland values. Two innovative wetland reclamation design case studies were also presented, described and illustrated, with particular reference to the Suncor fen and pond 1 marsh. It was concluded that future work will involve finalizing site investigation and designs, as well as construction, vegetation, and monitoring. figs.

  14. Cyberbullying : a faceta de um fenómeno em jovens universitários portugueses

    OpenAIRE

    Francisco, Sofia Mateus

    2012-01-01

    Tese de mestrado, Psicologia (Secção de Psicologia da Educação e da Orientação), Universidade de Lisboa, Faculdade de Psicologia, 2012 Com a crescente utilização das novas tecnologias de informação e comunicação (TIC) nascem grandes vantagens para os jovens, mas também a esta utilização acrescem alguns riscos. Um desses riscos diz respeito ao cyberbullying. Assim, o presente estudo pretende dar a conhecer o fenómeno em estudantes do ensino superior, através da aplicação do Questionário de ...

  15. El Quijote y el fenómeno del quijotismo (Don Quixote and Quixotism Phenomenon

    Directory of Open Access Journals (Sweden)

    Ruiz Fernández, Jesús

    2013-12-01

    Full Text Available Resumen: Estudia el presente artículo el fenómeno del quijotismo, ingrediente de la razón, y, por tanto, del comportamiento humano. Pero distingue entre el error del quijotismo estático y el sano proceder del dinámico. Para ello se vale del concepto de razón vital de Ortega y Gasset, así como del Quijote. Con respecto al primero, amplía la utilización que de la magna obra podía haber hecho y no hizo el ilustre filósofo. Y sobre el segundo, destaca sus insuficiencias de contenido, por no haber alcanzado el quijotismo dinámico, es decir, porque, queriendo criticar el idealismo desmedido del caballero manchego, termina por proponer otro quijote. De cualquier forma, el artículo señala cómo el irónico fenómeno del quijotismo no es un juego, para lo cual discute ciertas interpretaciones recientes del Quijote. Abstract: This article studies Quixotism phenomenon, ingredient of vital reason, and, consequently, of human behaviour. However, it distinguishes between the mistake of static quixotism and the right conduct of the dynamic one. In order to do so, it makes use of Ortega y Gasset's concept of Vital Reason, and Don Quixotes as well. Concerning the first one, it highlights the insufficiency of its content since it has not fulfilled the dynamic quixotism, that is to say, because, with the intention to criticize La Manchas Knights excessive idealism, it ends up proposing other quixotic person. Anyway, this article points out how the ironic quixotism phenomenon is not a game, for which reason it discusses certain Don Quixotes recent interpretations.

  16. Turismo religioso: fenómeno social y económico

    Directory of Open Access Journals (Sweden)

    Sandra Maribel Tobón Perilla

    2013-12-01

    Full Text Available El turismo religioso, como fenómeno social y económico, ha cobrado interés entre académicos y empresarios por las dinámicas que ha generado en las comunidades receptoras de visitantes. Para los primeros, el interés radica en el estudio de las motivaciones, intereses y necesidades espirituales o culturales que parecen haber despertado los centros religiosos; para los segundos, el impacto económico y las oportunidades de rentas adicionales que generan los visitantes, creando nuevas oportunidades de negocios y fuentes de ingresos y empleo para las comunidades aledañas. Este documento hace una revisión a la bibliografía sobre el tema de turismo religioso en el mundo, para lo cual se consultaron las bases de datos ScienceDirect, Jstor, Ebsco, ProQuest y Google Académico, a fin de rastrear las publicaciones más relevantes y estudios empíricos sobre el tema, haciendo un recorrido desde 1963 hasta 2013. Se concluye que el turismo religioso es un fenómeno que tiene su antecedente en el peregrinaje a centros religiosos, pero donde además de las motivaciones, netamente religiosas –ofrecer un sacrificio, obtener un beneficio divino o expiar pecados–, existe un interés cultural, en términos de conocer centros históricos o profundizar sobre las raíces de un credo religioso. Adicionalmente, se observa cómo el turismo religioso se ha convertido en un motor de desarrollo económico de las ciudades receptoras de viajeros a sitios religioso.

  17. Turismo religioso: fenómeno social y económico

    Directory of Open Access Journals (Sweden)

    Sandra Maribel Tobón Perilla

    2013-11-01

    Full Text Available El turismo religioso, como fenómeno social y económico, ha cobrado interés entre académicos y empresarios por las dinámicas que ha generado en las comunidades receptoras de visitantes. Para los primeros, el interés radica en el estudio de las motivaciones, intereses y necesidades espirituales o culturales que parecen haber despertado los centros religiosos; para los segundos, el impacto económico y las oportunidades de rentas adicionales que generan los visitantes, creando nuevas oportunidades de negocios y fuentes de ingresos y empleo para las comunidades aledañas. Este documento hace una revisión a la bibliografía sobre el tema de turismo religioso en el mundo, para lo cual se consultaron las bases de datos ScienceDirect, Jstor, Ebsco, ProQuest y Google Académico, a fin de rastrear las publicaciones más relevantes y estudios empíricos sobre el tema, haciendo un recorrido desde 1963 hasta 2013. Se concluye que el turismo religioso es un fenómeno que tiene su antecedente en el peregrinaje a centros religiosos, pero donde además de las motivaciones, netamente religiosas –ofrecer un sacrificio, obtener un beneficio divino o expiar pecados–, existe un interés cultural, en términos de conocer centros históricos o profundizar sobre las raíces de un credo religioso. Adicionalmente, se observa cómo el turismo religioso se ha convertido en un motor de desarrollo económico de las ciudades receptoras de viajeros a sitios religioso.

  18. Análisis del fenómeno de la violencia contra los ancianos

    Directory of Open Access Journals (Sweden)

    Celín Pérez Nájera

    2010-12-01

    Full Text Available El artículo presenta una revisión bibliográfica sobre el impacto social de la violencia contra los ancianos, desde la óptica criminológica. En el trabajo se utilizó como método investigativo el enfoque dialéctico-materialista de la realidad, que facilitó el engranaje de toda la investigación en diferentes etapas. Las valoraciones generalizadoras y sistematizadoras se elaboraron desde los enfoques modelativo y sistémico-estructural. Luego de analizar la diversidad de conceptos de violencia, se estableció una definición desde una formación social e histórica; existen dos principios que distinguen sus características: uno que la concibe como un fenómeno de carácter social y el teórico-ecológico, que consiste en el empleo de la fuerza física, económica o política, e implica el abuso de poder cómo único método para resolver el conflicto. Así mismo, se examinó el comportamiento de la violencia contra los ancianos en diversos países: España, Estados Unidos, Perú, Brasil, Panamá, Argentina, Colombia, Chile y Cuba. En general, son alarmantes las cifras de incidencia del fenómeno. De igual forma, en Cuba crece la victimización sobre los ancianos. Se aprecia como manifestación fundamental la violencia psicológica o emocional. Aunque existen mecanismos de denuncia, falta de divulgación y sistematicidad de acciones, que permitan enfrentar la incidencia de este mal social, que afecta a dicho grupo de riesgo de la violencia.

  19. Changes of phosphatidylcholine and fatty acids in germ cells during testicular maturation in three developmental male morphotypes of Macrobrachium rosenbergii revealed by imaging mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Tanapan Siangcham

    Full Text Available Testis maturation, germ cell development and function of sperm, are related to lipid composition. Phosphatidylcholines (PCs play a key role in the structure and function of testes. As well, increases of polyunsaturated fatty acids (PUFA and highly unsaturated fatty acids (HUFA, especially arachidonic acid (ARA, eicosapentaenoic acid (EPA, and docosahexaenoic acid (DHA are essential for male fertility. This study is the first report to show the composition and distribution of PCs and total fatty acids (FAs in three groups of seminiferous tubules (STs classified by cellular associations [i.e., A (STs with mostly early germ cells, B (STs with mostly spermatids, and C (STs with spermatozoa], in three morphotypes of Macrobrachium rosenbergii, [i.e., small male (SM, orange claw male (OC, and blue claw male (BC]. Thin layer chromatography exhibited levels of PCs reaching maxima in STs of group B. Imaging mass spectrometry showed remarkably high signals corresponding to PC (16:0/18:1, PC (18:0/18:2, PC (18:2/20:5, and PC (16:0/22:6 in STs of groups A and B. Moreover, most signals were detected in the early developing cells and the intertubular area, but not at the area containing spermatozoa. Finally, gas chromatography-mass spectrometry indicated that the major FAs present in the testes were composed of 14:0, 16:0, 17:0, 18:0, 16:1, 18:1, 18:2, 20:1, 20:2, 20:4, 20:5, and 22:6. The testes of OC contained the greatest amounts of these FAs while the testes of BC contained the least amounts of these FAs, and there was more EPA (20:5 in the testes of SM and OC than those in the BC. The increasing amounts of FAs in the SM and OC indicate that they are important for spermatogenesis and spermiogenesis. This knowledge will be useful in formulating diets containing PUFA and HUFA for prawn broodstocks in order to improve testis development, and lead to increased male fecundity.

  20. Changes of phosphatidylcholine and fatty acids in germ cells during testicular maturation in three developmental male morphotypes of Macrobrachium rosenbergii revealed by imaging mass spectrometry.

    Science.gov (United States)

    Siangcham, Tanapan; Chansela, Piyachat; Hayasaka, Takahiro; Masaki, Noritaka; Sroyraya, Morakot; Poljaroen, Jaruwan; Suwansa-ard, Saowaros; Engsusophon, Attakorn; Hanna, Peter J; Sobhon, Prasert; Setou, Mitsutoshi

    2015-01-01

    Testis maturation, germ cell development and function of sperm, are related to lipid composition. Phosphatidylcholines (PCs) play a key role in the structure and function of testes. As well, increases of polyunsaturated fatty acids (PUFA) and highly unsaturated fatty acids (HUFA), especially arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are essential for male fertility. This study is the first report to show the composition and distribution of PCs and total fatty acids (FAs) in three groups of seminiferous tubules (STs) classified by cellular associations [i.e., A (STs with mostly early germ cells), B (STs with mostly spermatids), and C (STs with spermatozoa)], in three morphotypes of Macrobrachium rosenbergii, [i.e., small male (SM), orange claw male (OC), and blue claw male (BC)]. Thin layer chromatography exhibited levels of PCs reaching maxima in STs of group B. Imaging mass spectrometry showed remarkably high signals corresponding to PC (16:0/18:1), PC (18:0/18:2), PC (18:2/20:5), and PC (16:0/22:6) in STs of groups A and B. Moreover, most signals were detected in the early developing cells and the intertubular area, but not at the area containing spermatozoa. Finally, gas chromatography-mass spectrometry indicated that the major FAs present in the testes were composed of 14:0, 16:0, 17:0, 18:0, 16:1, 18:1, 18:2, 20:1, 20:2, 20:4, 20:5, and 22:6. The testes of OC contained the greatest amounts of these FAs while the testes of BC contained the least amounts of these FAs, and there was more EPA (20:5) in the testes of SM and OC than those in the BC. The increasing amounts of FAs in the SM and OC indicate that they are important for spermatogenesis and spermiogenesis. This knowledge will be useful in formulating diets containing PUFA and HUFA for prawn broodstocks in order to improve testis development, and lead to increased male fecundity.

  1. Turn on, fade out - methane exchange in a coastal fen over a period of six years after rewetting

    Science.gov (United States)

    Jurasinski, Gerald; Glatzel, Stephan; Hahn, Juliane; Koch, Stefan; Koch, Marian; Koebsch, Franziska

    2016-04-01

    The rewetting of drained peatlands is widely regarded as an adequate measure for the mitigation of greenhouse gas emissions. Therefore, especially in NE Germany, many peatlands are being rewetted. Our knowledge about greenhouse gas exchange associated with rewetting is mainly based on short-term experiments or space-for-time substitutions. These approaches do not consider the transient character of ecosystem acclimatization to flooding by rewetting. Moreover data in this regard on coastal peatland ecosystems are sparse. Here, we present 7 years of data on CH4-exchange in a coastal fen after rewetting by flooding. On the site „Rodewiese", which is located within the NSG "Hütelmoor und Heiligensee" in the Northeast of Rostock, NE Germany, we have established a long term research observatory addressing atmospheric C-exchange. The site is part of the TERENO network. Since summer 2009 we determine CH4 fluxes with closed chambers distributed widely across the study site and CO2-exchange with eddy covariance as well as ancillary data on vegetation, hydrology, and biogeochemistry. This talk addresses the CH4-exchange over time whereas CO2-exchange data are presented by Koebsch et al. in the same session. Rewetting turned the site from a summer dry fen with mean annual water levels of around -0.08m into a shallow lake with water levels up to 0.60m. In the first year after flooding, we observed a substantial die-back of vegetation, especially in stands of Carex acutiformis. Flooding increased methane release rates to extremely high levels of up to 4.3 t ha-1 a-1 for sedge stands and 2.7 t ha-1 a-1 on average, which amounts to 75.6 t ha-1 a-1 in CO2-equivalents. Thereafter, the averaged annual CH4 emissions decreased asymptotically and where at an average of 0.5 t ha-1 a-1 (14 t ha-1 a-1 in CO2-equivalents) in 2015. Factoring in the NEE of the growing season (from Eddy measurements) suggests that the system may be slightly above neutral with respect to the greenhouse

  2. Differential molecular responses of rice and wheat coleoptiles to anoxia reveal novel metabolic adaptations in amino acid metabolism for tissue tolerance.

    Science.gov (United States)

    Shingaki-Wells, Rachel N; Huang, Shaobai; Taylor, Nicolas L; Carroll, Adam J; Zhou, Wenxu; Millar, A Harvey

    2011-08-01

    Rice (Oryza sativa) and wheat (Triticum aestivum) are the most important starch crops in world agriculture. While both germinate with an anatomically similar coleoptile, this tissue defines the early anoxia tolerance of rice and the anoxia intolerance of wheat seedlings. We combined protein and metabolite profiling analysis to compare the differences in response to anoxia between the rice and wheat coleoptiles. Rice coleoptiles responded to anoxia dramatically, not only at the level of protein synthesis but also at the level of altered metabolite pools, while the wheat response to anoxia was slight in comparison. We found significant increases in the abundance of proteins in rice coleoptiles related to protein translation and antioxidant defense and an accumulation of a set of enzymes involved in serine, glycine, and alanine biosynthesis from glyceraldehyde-3-phosphate or pyruvate, which correlates with an observed accumulation of these amino acids in anoxic rice. We show a positive effect on wheat root anoxia tolerance by exogenous addition of these amino acids, indicating that their synthesis could be linked to rice anoxia tolerance. The potential role of amino acid biosynthesis contributing to anoxia tolerance in cells is discussed.

  3. Global genome analysis of the shikimic acid pathway reveals greater gene loss in host-associated than in free-living bacteria

    Directory of Open Access Journals (Sweden)

    Amin Bijal

    2010-11-01

    Full Text Available Abstract Background A central tenet in biochemistry for over 50 years has held that microorganisms, plants and, more recently, certain apicomplexan parasites synthesize essential aromatic compounds via elaboration of a complete shikimic acid pathway, whereas metazoans lacking this pathway require a dietary source of these compounds. The large number of sequenced bacterial and archaean genomes now available for comparative genomic analyses allows the fundamentals of this contention to be tested in prokaryotes. Using Hidden Markov Model profiles (HMM profiles to identify all known enzymes of the pathway, we report the presence of genes encoding shikimate pathway enzymes in the hypothetical proteomes constructed from the genomes of 488 sequenced prokaryotes. Results Amongst free-living prokaryotes most Bacteria possess, as expected, genes encoding a complete shikimic acid pathway, whereas of the culturable Archaea, only one was found to have a complete complement of recognisable enzymes in its predicted proteome. It may be that in the Archaea, the primary amino-acid sequences of enzymes of the pathway are highly divergent and so are not detected by HMM profiles. Alternatively, structurally unrelated (non-orthologous proteins might be performing the same biochemical functions as those encoding recognized genes of the shikimate pathway. Most surprisingly, 30% of host-associated (mutualistic, commensal and pathogenic bacteria likewise do not possess a complete shikimic acid pathway. Many of these microbes show some degree of genome reduction, suggesting that these host-associated bacteria might sequester essential aromatic compounds from a parasitised host, as a 'shared metabolic adaptation' in mutualistic symbiosis, or obtain them from other consorts having the complete biosynthetic pathway. The HMM results gave 84% agreement when compared against data in the highly curated BioCyc reference database of genomes and metabolic pathways. Conclusions

  4. Metabolomics using GC-TOF-MS followed by subsequent GC-FID and HILIC-MS/MS analysis revealed significantly altered fatty acid and phospholipid species profiles in plasma of smokers.

    Science.gov (United States)

    Müller, Daniel C; Degen, Christian; Scherer, Gerhard; Jahreis, Gerhard; Niessner, Reinhard; Scherer, Max

    2014-09-01

    Mass spectrometry is an ideal tool for investigations of the metabolome in human plasma. To investigate the impact of smoking on the human metabolome, we performed an untargeted metabolic fingerprinting using GC-TOF-MS with EDTA-plasma samples from 25 smokers and 25 non-smokers. The observed elevated levels in the monounsaturated fatty acids (MUFAs) in smokers were verified by a targeted analysis using GC-FID, which revealed also significantly alterations in saturated and polyunsaturated fatty acids in smokers (p<0.05, Mann-Whitney U test). Since the main fraction of fatty acids in plasma is esterified to phospholipids, we analyzed phosphatidylcholine (PC) and phosphatidylethanolamine (PE) species composition in the plasma samples of the same subjects. The profiles of 39 PC and 40 PE species were analyzed with a newly developed and validated HILIC-ESI-MS/MS method. We were able to baseline separate the two lipid classes (PC from PE) by maintaining co-elution of individual lipid species of each class. The method shows a linear range from 0.5μM to 2000μM and an inter- and intraday coefficient of variation (CV)<20% across all analytes. Application of the validated method to the plasma samples of smokers and non-smokers, derived from a diet-controlled smoking study, revealed significantly elevated levels of PC and PE species containing MUFAs in smokers. In summary, we could demonstrate that there is a significantly altered total fatty acid profile, with increased MUFAs, in the plasma of smokers compared to non-smokers. Results obtained with the new HILIC-MS/MS method indicate that the altered fatty acid profile is also reflected in the PC and PE profile of smokers.

  5. Expression pattern of NMDA receptors reveals antiepileptic potential of apigenin 8-C-glucoside and chlorogenic acid in pilocarpine induced epileptic mice.

    Science.gov (United States)

    Aseervatham, G Smilin Bell; Suryakala, U; Doulethunisha; Sundaram, S; Bose, P Chandra; Sivasudha, T

    2016-08-01

    The present study was aimed to evaluate the effect of apigenin 8-C-glucoside (Vitexin) and chlorogenic acid on epileptic mice induced by pilocarpine and explored its possible mechanisms. Intraperitonial administration of pilocarpine (85mg/kg) induced seizure in mice was assessed by behavior observations, which is significantly (p>0.05) reduced by apigenin 8-C-glucoside (AP8CG) (10mg/kg) and chlorogenic acid (CA) (5mg/kg), similar to diazepam. Seizure was accompanied by an imbalance in the levels of Gamma-aminobutyric acid (GABA) and glutamate in the pilocarpine administered group. Moreover, convulsion along with reduced acetylcholinesterase, increased monoamine oxidase and oxidative stress was observed in epileptic mice brain. AP8CG and CA significantly restored back to normal levels even at lower doses. Further, increased lipid peroxidation and nitrite content was also significantly attenuated by AP8CG and CA. However, CA was found to be more effective when compared to AP8CG. In addition, the mRNA expression of N-methyl-d-aspartate receptor (NMDAR), mGluR1 and mGlu5 was significantly (P≤0.05) inhibited by AP8CG and CA in a lower dose. The mRNA expression of GRIK1 did not differ significantly in any of the group and showed a similar pattern of expression. Our result shows that AP8CG and CA selectively inhibit NMDAR, mGluR1 and mGlu5 expression. Modification in the provoked NMDAR calcium response coupled with neuronal death. Hence, these findings underline that the polyphenolics, AP8CG and CA have exerted antiepileptic and neuroprotective activity by suppressing glutamate receptors.

  6. Proteomic Analysis of Plasma from California Sea Lions (Zalophus californianus Reveals Apolipoprotein E as a Candidate Biomarker of Chronic Domoic Acid Toxicosis.

    Directory of Open Access Journals (Sweden)

    Benjamin A Neely

    Full Text Available Domoic acid toxicosis (DAT in California sea lions (Zalophus californianus is caused by exposure to the marine biotoxin domoic acid and has been linked to massive stranding events and mortality. Diagnosis is based on clinical signs in addition to the presence of domoic acid in body fluids. Chronic DAT further is characterized by reoccurring seizures progressing to status epilepticus. Diagnosis of chronic DAT is often slow and problematic, and minimally invasive tests for DAT have been the focus of numerous recent biomarker studies. The goal of this study was to retrospectively profile plasma proteins in a population of sea lions with chronic DAT and those without DAT using two dimensional gel electrophoresis to discover whether individual, multiple, or combinations of protein and clinical data could be utilized to identify sea lions with DAT. Using a training set of 32 sea lion sera, 20 proteins and their isoforms were identified that were significantly different between the two groups (p<0.05. Interestingly, 11 apolipoprotein E (ApoE charge forms were decreased in DAT samples, indicating that ApoE charge form distributions may be important in the progression of DAT. In order to develop a classifier of chronic DAT, an independent blinded test set of 20 sea lions, seven with chronic DAT, was used to validate models utilizing ApoE charge forms and eosinophil counts. The resulting support vector machine had high sensitivity (85.7% with 92.3% negative predictive value and high specificity (92.3% with 85.7% positive predictive value. These results suggest that ApoE and eosinophil counts along with machine learning can perform as a robust and accurate tool to diagnose chronic DAT. Although this analysis is specifically focused on blood biomarkers and routine clinical data, the results demonstrate promise for future studies combining additional variables in multidimensional space to create robust classifiers.

  7. El fenómeno "El Niño" 97-98 y sus efectos en las costas ecuatorianas

    OpenAIRE

    Soledispa, B.

    2000-01-01

    En este artículo se presentan los resultados de un reconocimiento geológico llevado a cabo en las playas de Salinas, La Libertad, Manglaralto, Montañita y Manta, en el que se determinó los efectos producidos por la presencia del último Fenómeno "El Niño" 97-98.

  8. El fenómeno recurrente de Tsingou, Fermi, Pasta, Ulam y el Déjà vu

    Directory of Open Access Journals (Sweden)

    Máximo Agüero

    2010-01-01

    Full Text Available Se proporciona una visión divulgativa de la investigación para comprobar el teorema ergódico sobre la equiparticion de la energía en un sistema de muchos grados de libertad. Tsingou, Fermi, Pasta y Ulam (tfpu, en Los Álamos, New Mexico, durante los años de la segunda postguerra, estudiando el fenómeno de trasmisión de calor en sólidos y con el fin de comprobar el teorema ergódico, se apoyaron en cálculos numéricos sobre un sistema discreto de masas unidas por fuerzas no lineales. Encontraron un fenómeno extraño que fue denominado como fenómeno recurrente de tfpu. Esta investigación puso la primera piedra angular en el rápido desarrollo de la física nolineal con estructuras de ondas solitarias y también en el nuevo método de investigación mediante la experimentación numérica. El fenómeno recurrente podría tener su análogo en la sensación repentina fisiológica llamado "Déjà vu".

  9. Screening of Phenolic Compounds Reveals Inhibitory Activity of Nordihydroguaiaretic Acid Against Three Enzymes Involved in the Regulation of Blood Glucose Level.

    Science.gov (United States)

    Roškar, Irena; Štrukelj, Borut; Lunder, Mojca

    2016-03-01

    In this work we have focused on the inhibition of three different enzymes with a role in postprandial glucose management: α-amylase, α-glucosidase and dipeptidyl peptidase 4. The assortment of 29 monomeric phenolic compounds was first screened at a single concentration. Next, the IC50 values of tested compounds were evaluated for compounds that considerably inhibited any of the enzymes. Nordihydroguaiaretic acid, a phenolic compound abundant in Creosote bush Larrea tridentata, possessed inhibitory activity for all tested enzymes. This in vitro mechanism of action supports traditional use of Creosote bush in diabetes treatment.

  10. A fluorescence-coupled assay for gamma aminobutyric acid (GABA reveals metabolic stress-induced modulation of GABA content in neuroendocrine cancer.

    Directory of Open Access Journals (Sweden)

    Joseph E Ippolito

    Full Text Available Pathways involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA have been implicated in the pathogenesis of high grade neuroendocrine (NE neoplasms as well as neoplasms from a non-NE lineage. Using The Cancer Genome Atlas, overexpression of the GABA synthetic enzyme, glutamate decarboxylase 1 (GAD1, was found to be associated with decreased disease free-survival in prostate adenocarcinoma and decreased overall survival in clear cell renal cell carcinomas. Furthermore, GAD1 was found to be expressed in castrate-resistant prostate cancer cell lines, but not androgen-responsive cell lines. Using a novel fluorescence-coupled enzymatic microplate assay for GABA mediated through reduction of resazurin in a prostate neuroendocrine carcinoma (PNEC cell line, acid microenvironment-induced stress increased GABA levels while alkaline microenvironment-induced stress decreased GABA through modulation of GAD1 and glutamine synthetase (GLUL activities. Moreover, glutamine but not glucose deprivation decreased GABA through modulation of GLUL. Consistent with evidence in prokaryotic and eukaryotic organisms that GABA synthesis mediated through GAD1 may play a crucial role in surviving stress, GABA may be an important mediator of stress survival in neoplasms. These findings identify GABA synthesis and metabolism as a potentially important pathway for regulating cancer cell stress response as well as a potential target for therapeutic strategies.

  11. New insights into the biogeochemistry of extremely acidic environments revealed by a combined cultivation-based and culture-independent study of two stratified pit lakes.

    Science.gov (United States)

    Falagán, Carmen; Sánchez-España, Javier; Johnson, David Barrie

    2014-01-01

    The indigenous microbial communities of two extremely acidic, metal-rich stratified pit lakes, located in the Iberian Pyrite Belt (Spain), were identified, and their roles in mediating transformations of carbon, iron, and sulfur were confirmed. A combined cultivation-based and culture-independent approach was used to elucidate microbial communities at different depths and to examine the physiologies of isolates, which included representatives of at least one novel genus and several species of acidophilic Bacteria. Phosphate availability correlated with redox transformations of iron, and this (rather than solar radiation) dictated where primary production was concentrated. Carbon fixed and released as organic compounds by acidophilic phototrophs acted as electron donors for acidophilic heterotrophic prokaryotes, many of which catalyzed the dissimilatory reduction in ferric iron; the ferrous iron generated was re-oxidized by chemolithotrophic acidophiles. Bacteria that catalyze redox transformations of sulfur were also identified, although these Bacteria appeared to be less abundant than the iron oxidizers/reducers. Primary production and microbial numbers were greatest, and biogeochemical transformation of carbon, iron, and sulfur, most intense, within a zone of c. 8-10 m depth, close to the chemocline, in both pit lakes. Archaea detected in sediments included two Thaumarchaeota clones, indicating that members of this recently described phylum can inhabit extremely acidic environments.

  12. A fluorescence-coupled assay for gamma aminobutyric acid (GABA) reveals metabolic stress-induced modulation of GABA content in neuroendocrine cancer.

    Science.gov (United States)

    Ippolito, Joseph E; Piwnica-Worms, David

    2014-01-01

    Pathways involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA) have been implicated in the pathogenesis of high grade neuroendocrine (NE) neoplasms as well as neoplasms from a non-NE lineage. Using The Cancer Genome Atlas, overexpression of the GABA synthetic enzyme, glutamate decarboxylase 1 (GAD1), was found to be associated with decreased disease free-survival in prostate adenocarcinoma and decreased overall survival in clear cell renal cell carcinomas. Furthermore, GAD1 was found to be expressed in castrate-resistant prostate cancer cell lines, but not androgen-responsive cell lines. Using a novel fluorescence-coupled enzymatic microplate assay for GABA mediated through reduction of resazurin in a prostate neuroendocrine carcinoma (PNEC) cell line, acid microenvironment-induced stress increased GABA levels while alkaline microenvironment-induced stress decreased GABA through modulation of GAD1 and glutamine synthetase (GLUL) activities. Moreover, glutamine but not glucose deprivation decreased GABA through modulation of GLUL. Consistent with evidence in prokaryotic and eukaryotic organisms that GABA synthesis mediated through GAD1 may play a crucial role in surviving stress, GABA may be an important mediator of stress survival in neoplasms. These findings identify GABA synthesis and metabolism as a potentially important pathway for regulating cancer cell stress response as well as a potential target for therapeutic strategies.

  13. Chlorobaculum tepidum Modulates Amino Acid Composition in Response to Energy Availability, as Revealed by a Systematic Exploration of the Energy Landscape of Phototrophic Sulfur Oxidation.

    Science.gov (United States)

    Levy, Amalie T; Lee, Kelvin H; Hanson, Thomas E

    2016-11-01

    Microbial sulfur metabolism, particularly the formation and consumption of insoluble elemental sulfur (S(0)), is an important biogeochemical engine that has been harnessed for applications ranging from bioleaching and biomining to remediation of waste streams. Chlorobaculum tepidum, a low-light-adapted photoautolithotrophic sulfur-oxidizing bacterium, oxidizes multiple sulfur species and displays a preference for more reduced electron donors: sulfide > S(0) > thiosulfate. To understand this preference in the context of light energy availability, an "energy landscape" of phototrophic sulfur oxidation was constructed by varying electron donor identity, light flux, and culture duration. Biomass and cellular parameters of C. tepidum cultures grown across this landscape were analyzed. From these data, a correction factor for colorimetric protein assays was developed, enabling more accurate biomass measurements for C. tepidum, as well as other organisms. C. tepidum's bulk amino acid composition correlated with energy landscape parameters, including a tendency toward less energetically expensive amino acids under reduced light flux. This correlation, paired with an observation of increased cell size and storage carbon production under electron-rich growth conditions, suggests that C. tepidum has evolved to cope with changing energy availability by tuning its proteome for energetic efficiency and storing compounds for leaner times.

  14. The hydrological and geochemical isolation of a freshwater bog within a saline fen in north-eastern Alberta

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    S.J. Scarlett

    2013-10-01

    Full Text Available In the oil sands development region near Fort McMurray, Alberta, wetlands cover ~62 % of the landscape, and ~95 % of these wetlands are peatlands. A saline fen was studied as a reference site for peatland reclamation. Despite highly saline conditions, a freshwater bog was observed in the path of local saline groundwater flow. The purpose of this study was to identify the hydrological controls that have allowed the development and persistence of a bog in this setting. The presence of bog vegetation and its dilute water chemistry suggest that saline groundwater from the fen rarely enters the bog, which functions predominantly as a groundwater recharge system. Chloride (Cl– and sodium (Na+ were the dominant ions in fen water, with concentrations averaging 5394 and 2307 mg L-1, respectively, while the concentrations in bog water were 5 and 4 mg L-1, respectively. These concentrations were reflected by salinity and electrical conductivity measurements, which in the fen averaged 9.3 ppt, and 15.8 mS cm-1, respectively, and in the bog averaged 0.1 ppt and 0.3 mS cm-1, respectively. A small ridge in the mineral substratum was found at the fen–bog margin, which created a persistent groundwater mound. Under the dry conditions experienced in early summer, groundwater flow was directed away from the bog at a rate of 14.6 mm day-1. The convex water table at the fen-bog margin impeded flow of saline water into the bog and instead directed it around the bog margin. However, the groundwater mound was eliminated during flooding in autumn, when the horizontal hydraulic gradient across the margin became negligible, suggesting the possibility of saline water ingress into the bog under these conditions.

  15. Crystal Structures of Xanthomonas campestris OleA Reveal Features That Promote Head-to-Head Condensation of Two Long-Chain Fatty Acids

    Energy Technology Data Exchange (ETDEWEB)

    Goblirsch, Brandon R.; Frias, Janice A.; Wackett, Lawrence P.; Wilmot, Carrie M. (UMM)

    2012-10-25

    OleA is a thiolase superfamily enzyme that has been shown to catalyze the condensation of two long-chain fatty acyl-coenzyme A (CoA) substrates. The enzyme is part of a larger gene cluster responsible for generating long-chain olefin products, a potential biofuel precursor. In thiolase superfamily enzymes, catalysis is achieved via a ping-pong mechanism. The first substrate forms a covalent intermediate with an active site cysteine that is followed by reaction with the second substrate. For OleA, this conjugation proceeds by a nondecarboxylative Claisen condensation. The OleA from Xanthomonas campestris has been crystallized and its structure determined, along with inhibitor-bound and xenon-derivatized structures, to improve our understanding of substrate positioning in the context of enzyme turnover. OleA is the first characterized thiolase superfamily member that has two long-chain alkyl substrates that need to be bound simultaneously and therefore uniquely requires an additional alkyl binding channel. The location of the fatty acid biosynthesis inhibitor, cerulenin, that possesses an alkyl chain length in the range of known OleA substrates, in conjunction with a single xenon binding site, leads to the putative assignment of this novel alkyl binding channel. Structural overlays between the OleA homologues, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase and the fatty acid biosynthesis enzyme FabH, allow assignment of the two remaining channels: one for the thioester-containing pantetheinate arm and the second for the alkyl group of one substrate. A short {beta}-hairpin region is ordered in only one of the crystal forms, and that may suggest open and closed states relevant for substrate binding. Cys143 is the conserved catalytic cysteine within the superfamily, and the site of alkylation by cerulenin. The alkylated structure suggests that a glutamic acid residue (Glu117{beta}) likely promotes Claisen condensation by acting as the catalytic base. Unexpectedly

  16. Crystal Structures of Xanthomonas campestris OleA Reveal Features That Promote Head-to-Head Condensation of Two Long-Chain Fatty Acids

    Energy Technology Data Exchange (ETDEWEB)

    Goblirsch, BR; Frias, JA; Wackett, LP; Wilmot, CM

    2012-05-22

    OleA is a thiolase superfamily enzyme that has been shown to catalyze the condensation of two long-chain fatty acylcoenzyme A (CoA) substrates. The enzyme is part of a larger gene cluster responsible for generating long-chain olefin products, a potential biofuel precursor. In thiolase superfamily enzymes, catalysis is achieved via a ping-pong mechanism. The first substrate forms a covalent intermediate with an active site cysteine that is followed by reaction with the second substrate. For OleA, this conjugation proceeds by a nondecarboxylative Claisen condensation. The OleA from Xanthomonas campestris has been crystallized and its structure determined, along with inhibitor-bound and xenon-derivatized structures, to improve our understanding of substrate positioning in the context of enzyme turnover. OleA is the first characterized thiolase superfamily member that has two long-chain alkyl substrates that need to be bound simultaneously and therefore uniquely requires an additional alkyl binding channel. The location of the fatty acid biosynthesis inhibitor, cerulenin, that possesses an alkyl chain length in the range of known OleA substrates, in conjunction with a single xenon binding site, leads to the putative assignment of this novel alkyl binding channel. Structural overlays between the OleA homologues, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase and the fatty acid biosynthesis enzyme FabH, allow assignment of the two remaining channels: one for the thioester-containing pantetheinate arm and the second for the alkyl group of one substrate. A short beta-hairpin region is ordered in only one of the crystal forms, and that may suggest open and closed states relevant for substrate binding. Cys143 is the conserved catalytic cysteine within the superfamily, and the site of alkylation by cerulenin. The alkylated structure suggests that a glutamic acid residue (Glu117 beta) likely promotes Claisen condensation by acting as the catalytic base. Unexpectedly, Glu117

  17. Transcriptome analysis of H2O2-treated wheat seedlings reveals a H2O2-responsive fatty acid desaturase gene participating in powdery mildew resistance.

    Directory of Open Access Journals (Sweden)

    Aili Li

    Full Text Available Hydrogen peroxide (H(2O(2 plays important roles in plant biotic and abiotic stress responses. However, the effect of H(2O(2 stress on the bread wheat transcriptome is still lacking. To investigate the cellular and metabolic responses triggered by H(2O(2, we performed an mRNA tag analysis of wheat seedlings under 10 mM H(2O(2 treatment for 6 hour in one powdery mildew (PM resistant (PmA and two susceptible (Cha and Han lines. In total, 6,156, 6,875 and 3,276 transcripts were found to be differentially expressed in PmA, Han and Cha respectively. Among them, 260 genes exhibited consistent expression patterns in all three wheat lines and may represent a subset of basal H(2O(2 responsive genes that were associated with cell defense, signal transduction, photosynthesis, carbohydrate metabolism, lipid metabolism, redox homeostasis, and transport. Among genes specific to PmA, 'transport' activity was significantly enriched in Gene Ontology analysis. MapMan classification showed that, while both up- and down- regulations were observed for auxin, abscisic acid, and brassinolides signaling genes, the jasmonic acid and ethylene signaling pathway genes were all up-regulated, suggesting H(2O(2-enhanced JA/Et functions in PmA. To further study whether any of these genes were involved in wheat PM response, 19 H(2O(2-responsive putative defense related genes were assayed in wheat seedlings infected with Blumeria graminis f. sp. tritici (Bgt. Eight of these genes were found to be co-regulated by H(2O(2 and Bgt, among which a fatty acid desaturase gene TaFAD was then confirmed by virus induced gene silencing (VIGS to be required for the PM resistance. Together, our data presents the first global picture of the wheat transcriptome under H(2O(2 stress and uncovers potential links between H(2O(2 and Bgt responses, hence providing important candidate genes for the PM resistance in wheat.

  18. Ambiguity Revealed

    OpenAIRE

    Subir Bose; Matthew Polisson; Ludovic Renou

    2012-01-01

    We derive necessary and suffcient conditions for data sets composed of state-contingent prices and consumption to be consistent with two prominent models of decision making under ambiguity: variational preferences and smooth ambiguity. The revealed preference conditions for the maxmin expected utility and subjective expected utility models are characterized as special cases.

  19. Ambiguity revealed

    OpenAIRE

    Bayer, Ralph-C; Bose, Subir; Polisson, Matthew; Renou, Ludovic

    2013-01-01

    We derive necessary and sufficient conditions for data sets composed of state-contingent prices and consumption to be consistent with two prominent models of decision making under uncertainty: variational preferences and smooth ambiguity. The revealed preference conditions for subjective expected utility, maxmin expected utility, and multiplier preferences are characterised as special cases. We implement our tests on data from a portfolio choice experiment.

  20. Mouse sperm patch-clamp recordings reveal single Cl- channels sensitive to niflumic acid, a blocker of the sperm acrosome reaction.

    Science.gov (United States)

    Espinosa, F; de la Vega-Beltrán, J L; López-González, I; Delgado, R; Labarca, P; Darszon, A

    1998-04-10

    Ion channels lie at the heart of gamete signaling. Understanding their regulation will improve our knowledge of sperm physiology, and may lead to novel contraceptive strategies. Sperm are tiny (approximately 3 microm diameter) and, until now, direct evidence of ion channel activity in these cells was lacking. Using patch-clamp recording we document here, for the first time, the presence of cationic and anionic channels in mouse sperm. Anion selective channels were blocked by niflumic acid (NA) (IC50 = 11 microM). The blocker was effective also in inhibiting the acrosome reaction induced by the zona pellucida, GABA or progesterone. These observations suggest that Cl- channels participate in the sperm acrosome reaction in mammals.

  1. Proteome analysis of fatty liver in feed-deprived dairy cows reveals interaction of fuel sensing, calcium, fatty acid, and glycogen metabolism.

    Science.gov (United States)

    Kuhla, Björn; Albrecht, Dirk; Kuhla, Siegfried; Metges, Cornelia C

    2009-04-10

    The liver of dairy cows is involved in signaling the current hepatic metabolic state to the brain via metabolites and nerval afferents to control and adjust feed intake. Feed deprivation may result in mobilization of body reserves favoring hepatic steatosis. While the overall metabolic changes are well characterized, specific regulatory mechanisms are not readily understood. To identify molecular events associated with metabolic adaptation and the control of energy homeostasis, liver specimens from six ad libitum-fed and six feed-deprived cows were analyzed for selected metabolites, for the activation of AMP kinase, and for regulatory/regulated proteins using two-dimensional gel electrophoresis and MALDI-TOF-MS. Feed deprivation increased total liver fat and the calcium content, as well as augmented AMPK phosphorylation, while it decreased the contents of protein, glucose, glycogen, and cholesterol when expressed as a percentage of dry matter. Among 34 differentially expressed proteins identified, we found downregulation of proteins associated with fatty acid oxidation, glycolysis, electron transfer, protein degradation, and antigen processing, as well as cytoskeletal rearrangement. Proteins upregulated after feed deprivation included enzymes of the urea cycle, fatty acid or cholesterol transport proteins, an inhibitor of glycolysis, and previously unknown changes in calcium signaling network. Direct correlation was found between expression of glycolytic enzymes and glucose/glycogen content, whereas inverse correlation exists between expression of beta-oxidative enzymes and total liver fat content. In conclusion, the regulatory response of identified proteins may help to explain development and consequences of hepatic lipidosis but also offers novel candidates potentially involved in signaling for maintaining energy homeostasis.

  2. Methane Exchange in a Coastal Fen in the First Year after Flooding--A Systems Shift.

    Directory of Open Access Journals (Sweden)

    Juliane Hahn

    Full Text Available Peatland restoration can have several objectives, for example re-establishing the natural habitat, supporting unique biodiversity attributes or re-initiating key biogeochemical processes, which can ultimately lead to a reduction in greenhouse gas (GHG emissions. Every restoration measure, however, is itself a disturbance to the ecosystem.Here, we examine an ecosystem shift in a coastal fen at the southern Baltic Sea which was rewetted by flooding. The analyses are based on one year of bi-weekly closed chamber measurements of methane fluxes gathered at spots located in different vegetation stands. During measurement campaigns, we recorded data on water levels, peat temperatures, and chemical properties of peat water. In addition we analyzed the first 20 cm of peat before and after flooding for dry bulk density (DBD, content of organic matter and total amounts of carbon (C, nitrogen (N, sulfur (S, and other nutrients.Rewetting turned the site from a summer dry fen into a shallow lake with water levels up to 0.60 m. We observed a substantial die-back of vegetation, especially in stands of sedges (Carex acutiformis Ehrh. Concentrations of total organic carbon and nitrogen in the peat water, as well as dry bulk density and concentrations of C, N and S in the peat increased. In the first year after rewetting, the average annual exchange of methane amounted to 0.26 ± 0.06 kg m-2. This is equivalent to a 190-times increase in methane compared to pre-flooding conditions. Highest methane fluxes occurred in sedge stands which suffered from the heaviest die-back. None of the recorded environmental variables showed consistent relationships with the amounts of methane exchanged.Our results suggest that rewetting projects should be monitored not only with regard to vegetation development but also with respect to biogeochemical conditions. Further, high methane emissions that likely occur directly after rewetting by flooding should be considered when

  3. Holocene methane flux reconstruction from peat macrofossils at Siikaneva bog and fen, Finland

    Science.gov (United States)

    Mathijssen, Paul; Korrensalo, Aino; Tuittila, Eeva-Stiina; Väliranta, Minna; Mellais, Annina

    2015-04-01

    Previous studies have shown that a correlation exists between methane flux and peatland plant species abundance. Furthermore, it has been demonstrated that the composition of plant species or functional groups of species can be used as indicator for methane fluxes in peatlands, using weighted averaging. This method has the potential to be very useful in palaeoecological studies of peatlands as well. This method offers the possibility to reconstruct past methane flux based on vegetation remains still present in the peat archive and together with reconstructions of carbon accumulation can give a more complete picture of peatlands' carbon dynamics during the Holocene. Furthermore, effects of changes in hydrology or temperature on methane fluxes can be studied over much longer time scales, compared to what experimental setups allow for. For four peat cores from Siikaneva peatland in southern Finland, we reconstructed the methane flux during the Holocene. Two cores represent a part of the peatland that has currently a fen type vegetation. The other two cores were taken from a part of the peatland that has transformed into a bog, around 3.5 - 5.5 cal. year before present. The development of methane flux during the fen to bog transition is especially of interest. We used vegetation data and methane flux data from chamber measurement from all microtopographies found on Siikaneva and from a few similar peatlands in southern and central Finland as a training set. The plant species were classified into functional groups. Firstly, because it has been shown that usage of functional groups leads to better predictions of methane flux when compared to e.g. species or dominant species. Secondly, the information from the peat cores used as input for the reconstruction is based on progressively decomposed plant remains in subsequent peat layers, for which identification to species level is not always possible (most notably for sedges). We compare the predictive performance of two

  4. Feminización del fenómeno migratorio ecuatoriano

    Directory of Open Access Journals (Sweden)

    Jorge Moreno Egas

    2009-12-01

    Full Text Available La crítica situación económica y política del Ecuador en la última década del XX fue la coyuntura que agudizó el fenómeno migratorio presente desde mediados de ese siglo. América Latina, Norte América y en los últimos tiempos Europa, particularmente España e Italia son los lugares de destino de los ecuatorianos. Este hecho se caracteriza por ser amplio y diverso. Los migrantes provienen de todas las clases sociales, es multigeneracional y particularmente femenino. Los efectos de la crisis y situaciones particulares de violencia y marginación han obligado a las mujeres a buscar alternativas de trabajo fuera del país. La feminización del fenómeno migratorio, dentro o fuera de la legalidad, más allá de su lado bueno, - remesas para la familia que queda a tras, éxitos personales en los lugares de acogida y la perspectiva de reunificación de la familia -, coloca a las migrantes en situaciones de vulnerabilidad, origina rupturas familiares y pone en riesgo la seguridad de los niños por privárseles del papel protagónico que las madres cumplen en su crianza.___________________ABSTRACT:Ecuador’s critical economic and political situation during the last decade of the Twentieth Century was the trend that worsened the emigration phenomenon present from the middle of the century. Latin America, North America and, lately, Europe, particularly Spain and Italy, are the destinations for Ecuadorians. This fact is characterized by being broad and diverse. Emigrants come from all social classes, are multi-generational and particularly female. The effects of the crisis and the specific situations of violence and marginalization have forced women to seek options for work outside the country. The feminization of the emigration phenomenon inside or outside the law other than its good side – remittances to the family that stayed behind, personal success in the places where they are received and the perspective of reuniting with family

  5. Oral tolerance El fenómeno de la tolerancia oral

    Directory of Open Access Journals (Sweden)

    Martín Correa

    1989-03-01

    Full Text Available

    The phenomenon of decreased systemic Immune response to orally administered antigens is known as oral tolerance (OT. Though It was anecdotically described many years ago, the mechanisms and potential applications of OT are still mostly speculative. Specificity and thymus-dependence are among its most remarkable features. OT is manifested by the absence of systemic antibodies, of delayed type hypersensitivity and of proliferate responses toward the specific antigen. Potential mechanisms of OT have been grouped in three types, namely: Immunologic, gastrointestinal and individual. The most Important of the immunologic mechanisms might be the existence of counter-suppressive cells but their intimate functioning has not been thoroughly elucidated. The study of OT opens a wide research field with Implications for the immunoprophylaxis and Immunotherapy of many diseases.

    Se da el nombre de tolerancia oral al estado de respuesta inmune sistémica disminuida a antígenos administrados por la vía oral. Si bien el fenómeno fue descrito anecdóticamente desde hace muchos años, sus mecanismos y posibles aplicaciones todavía son materia de especulación. Entre sus características notables se destacan la especificidad y la timodependencia. La tolerancia se manifiesta por ausencia de anticuerpos sistémicos, de hipersensibilidad de tipo retardado y de respuestas proliferativas al antígeno específico. Los posibles mecanismos responsables de la tolerancia oral se han agrupado en tres tipos: inmunológicos, gastrointestinales e individuales. En cuanto a los inmunológicos, el más importante podría ser la existencia de las células contrasupresoras, pero los mecanismos íntimos de funcionamiento de éstas no están completamente elaborados. El estudio del fenómeno de la tolerancia oral abre un amplio campo

  6. Compuestos fenólicos del olivo (Olea europea

    Directory of Open Access Journals (Sweden)

    Maestro-Durán, R.

    1994-08-01

    Full Text Available Certain plant properties, such as the colour, the nutritional value, the resistance to microorganisms, the pharmacologic effects and the organoleptic character, are due to the phenolic compounds. It is interesting the study of phenolic compounds from olive because they:

    -Inhibit Gram+ microorganisms, such as Lactobacillus, which are involved in the fermentation of the olive fruit. -Inhibit the activity of cellulases and other enzymes. -Contribute to the stability and organoleptic character of virgin olive oil. -Inhibit the effect of microorganisms involved in the anaerobic depuration of vegetation water. Thus, the phenolic compounds are the major bothersome contaminants of these wastewater. -Have pharmacologic properties (to reduce blood pressure levels. -Are natural antioxidants.

    In the present review we describe the composition of the phenolic compounds from the olive fruit (pulp and seed, the olive oil and its by-products (vegetation water and rape and the olive leaves.

    Ciertas propiedades de las plantas, como el color, valor nutricional, autoprotección contra microorganismos, propiedades farmacológicas o caracteres organolépticos, son debidas a los compuestos fenólicos. Su estudio, en el caso del olivo, es de gran interés por diversas razones:

    -Por su carácter antibiótico, los fenoles de la aceituna inhiben los microorganismos Gram+, como Lactobacillus, necesarios para la fermentación de aceitunas de mesa. -Inhiben la acción de las celulasas y otras enzimas. -Son los responsables de la alta estabilidad de los aceites vírgenes de oliva, así como de alguno de sus caracteres organolépticos. -Inhiben la acción de los microorganismos responsables de la depuración anaerobia de los alpechines y son las sustancias contaminantes de estas aguas residuales cuya degradación para eliminar la DQO presenta más dificultades. -Tienen propiedades

  7. Novel Molecular Insights into Classical and Alternative Activation States of Microglia as Revealed by Stable Isotope Labeling by Amino Acids in Cell Culture (SILAC)-based Proteomics.

    Science.gov (United States)

    Bell-Temin, Harris; Culver-Cochran, Ashley E; Chaput, Dale; Carlson, Christina M; Kuehl, Melanie; Burkhardt, Brant R; Bickford, Paula C; Liu, Bin; Stevens, Stanley M

    2015-12-01

    Microglia, the resident immune cells of the brain, have been shown to display a complex spectrum of roles that span from neurotrophic to neurotoxic depending on their activation status. Microglia can be classified into four stages of activation, M1, which most closely matches the classical (pro-inflammatory) activation stage, and the alternative activation stages M2a, M2b, and M2c. The alternative activation stages have not yet been comprehensively analyzed through unbiased, global-scale protein expression profiling. In this study, BV2 mouse immortalized microglial cells were stimulated with agonists specific for each of the four stages and total protein expression for 4644 protein groups was quantified using SILAC-based proteomic analysis. After validating induction of the various stages through a targeted cytokine assay and Western blotting of activation states, the data revealed novel insights into the similarities and differences between the various states. The data identify several protein groups whose expression in the anti-inflammatory, pro-healing activation states are altered presumably to curtail inflammatory activation through differential protein expression, in the M2a state including CD74, LYN, SQST1, TLR2, and CD14. The differential expression of these proteins promotes healing, limits phagocytosis, and limits activation of reactive nitrogen species through toll-like receptor cascades. The M2c state appears to center around the down-regulation of a key member in the formation of actin-rich phagosomes, SLP-76. In addition, the proteomic data identified a novel activation marker, DAB2, which is involved in clathrin-mediated endocytosis and is significantly different between M2a and either M1 or M2b states. Western blot analysis of mouse primary microglia stimulated with the various agonists of the classical and alternative activation states revealed a similar trend of DAB2 expression compared with BV2 cells.

  8. As "propagandas do horror" e os fenômenos de massa contemporâneos

    Directory of Open Access Journals (Sweden)

    Ana Paula Avila Gomide

    2011-12-01

    Full Text Available Este trabalho teórico discute os fundamentos ligados a certas disposições psíquicas que subjazem aos fenômenos de massa contemporâneos, a partir da relação estabelecida entre o conto "Os Anões" e as propagandas antifumo, as denominadas "propagandas do terror", as quais são transmitidas por imagens que mostram o processo de definhamento e de decomposição do fumante. OS referenciais teóricos adotados são Theodor Adorno, Max Horkheimer e SigmundFreud. Pressupõe-se que, para a análise tanto do subtexto das mensagens quanto do conto, a tese sobre a história subterrânea do esclarecimento voltada à dominação do corpo e da natureza, e mais do "retorno do recalcado", lança luz sobre os elementos investigados.

  9. Carbonaceous thin film coating with Fe-N4 site for enhancement of dioxovanadium ion reduction

    Science.gov (United States)

    Maruyama, Jun; Hasegawa, Takahiro; Iwasaki, Satoshi; Fukuhara, Tomoko; Orikasa, Yuki; Uchimoto, Yoshiharu

    2016-08-01

    It has been found that carbonaceous materials containing a transition metal coordinated by 4 nitrogens in the square-planar configuration (metal-N4 site) on the surface possessed a catalytic activity for various electrochemical reactions related to energy conversion and storage; i.e., oxygen reduction, hydrogen evolution, and quite recently, the electrode reactions in vanadium redox flow batteries (VRFB). The catalyst for the VRFB positive electrode discharge reaction, i.e., the dioxovanadium ion reduction, was formed by coating the surface of cup-stack carbon nanotubes with a carbonaceous thin film with the Fe-N4 site generated by the sublimation, deposition, and pyrolysis of iron phthalocyanine. In this study, the influence of the physical properties of the catalyst on the electrochemical reactions was investigated to optimize the coating. With an increase in the coating, the specific surface area increased, whereas the pore size decreased. The surface Fe concentration was increased in spite of the Fe aggregation inside the carbon matrix. The catalytic activity enhancement was achieved due to the increase in the specific surface area and the surface Fe concentration, but was lowered due to the decrease in the pore size, which was disadvantageous for the penetration of the electrolyte and the mass transfer.

  10. El fenómeno de los periodistas ciudadanos en los conflictos armados actuales

    Directory of Open Access Journals (Sweden)

    Chema Suárez Serrano

    2016-01-01

    Full Text Available Muchas veces, las noticias difundidas por los llamados periodistas ciudadanos logran un enorme impacto en la opinión pública, hasta el punto de que las grandes empresas informativas ayudan a su difusión, especialmente en los conflictos armados. El auge de este fenómeno se debe a las facilidades que brindan las nuevas tecnologías digitales a los usuarios no especializados, que con sólo un teléfono con conexión a Internet gozan de un acceso inusitado tanto a la emisión como a la recepción de mensajes a escala mundial. Los tribunales de justicia han comenzado a otorgar a los ciudadanos la misma protección que a los profesionales, cuando se trata de la defensa del derecho a la libertad de expresión, y las Organizaciones Internacionales ya equiparan a ambos en derechos y obligaciones. Las nuevas tecnologías no sólo han cambiado el perfil de los conflictos armados; también obligan a replantearse quién es periodista, qué es el periodismo.

  11. Efectos ecológicos del fenómeno ENOS en Colombia

    Directory of Open Access Journals (Sweden)

    Yesid Carvajal

    2014-06-01

    Full Text Available El fenómeno ENOS, tiene un sustancial efecto sobre las variaciones del clima a nivel mundial; por lo tanto, no sorprende que sus efectos tengan un impacto ecológico y socioeconómico fuerte, alterando la seguridad alimentaria de los países a nivel mundial. Ante este panorama, es comprensible que haya despertado el mayor interés mundial, no sólo en los especialistas en meteorología y oceanografía sino también entre biólogos, ecólogos, físicos, matemáticos, agrónomos, hidrólogos, economistas, sociólogos y planificadores, entre otros. En el presente documento, se muestra algunos de los principales efectos ecológicos en Colombia durante las fases extremas cálida (El Niño y fría (La Niña, indicando que es una necesidad urgente, orientar la investigación en sus causas, consecuencias e impactos.

  12. El sesgo de subconfianza como fenómeno de dominio específico

    Directory of Open Access Journals (Sweden)

    Guillermo Macbeth

    2009-01-01

    Full Text Available Se define la calibración o confianza como la coincidencia o discrepancia entre el éxito subjetivo y el éxito objetivo que presenta una persona en la realización de una colecci ón de tareas. Las discrepancias entre uno y otro generan distorsiones conocidas como sesgos de la calibración. Cuando el éxito subjetivo predomina sobre el éxito objetivo se observa el sesgo de sobreconfianza. En el caso contrario, se observa el sesgo de subconfianza. Se presenta un estudio experimental que intenta decidir si el dominio es relevante para la disolución del sesgo de subconfianza. Los resultados indican que el domino es efectivamente relevante para reducir y eliminar esta distorsi ón del pensamiento humano. La exposición de los participantes a un modelo metacognitivo de calibración de domino específico logró disolver el sesgo. Cuando se empleó un modelo de dominio no específico, en cambio, el sesgo no se disolvió sino que se invirtió produciendo el sesgo de sobreconfianza. Se concluye que el sesgo de subconfianza es un fenómeno metacognitivo de dominio específico.

  13. El fenómeno del Greenwashing y su impacto sobre los consumidores

    Directory of Open Access Journals (Sweden)

    Moritz Hallama

    2011-07-01

    Full Text Available Hoy en día y mediante una publicidad sofisticada, las empresas tratan de proyectar una imagen respetuosa con el medio ambiente en la percepción de los consumidores. Esta imagen no refleja necesariamente la realidad. Se habla de “Greenwashing” cuando una empresa utiliza la ampliación selectiva de información medioambiental positiva con la finalidad de causar una imagen distorsionada donde los aspectos positivos predominan mas del debido. Este artículo pretende de abordar este fenómeno y avaluar su existencia, importancia y el efecto causado sobre los consumidores mediante el diseño de una metodología piloto para la investigación, aplicando ésta a una muestra de estudiantes. Los resultados indican que la imagen transmitida por la publicidad de cinco grandes empresas seleccionadas contrasta con ejemplos de mala gestión y que esta manipulación influye en la percepción que tiene la muestra encuestada. Los estudiantes de Ciencias Ambientales encuestados presentan ser ligeramente más resistentes contra el Greenwashing debido a su formación, pero también incorporan mayoritariamente el discurso oficial procedente de las relaciones públicas empresariales.

  14. El patrimonio como fenómeno socio-cultural y su contextualización

    Directory of Open Access Journals (Sweden)

    Nurys de los Angeles Valcárcel Leyva

    2011-01-01

    Full Text Available El humanista del presente requiere sólidas bases académicas, que le permitan desarrollar la práctica de enfrentamiento a la aculturación neoliberal. Se ofrecen análisis y valoraciones en torno al patrimonio, los cuales se consideran referentes que fundamentan científicamente la necesidad del sujeto cultural de defender su pertenencia identitaria. El patrimonio se aborda como fenómeno que se desarrolla a instancias del proceso de relaciones entre sociedad y cultura, como resultado de la contradicción conservaciónrenovación inherente al desarrollo humano. Las formulaciones conceptuales y de reconceptualización, se presentan desde la apoyatura científica que ofrecen ciencias particulares como la filosofía, antropología, sociología y otras, éstas contribuyen a la interpretación y análisis crítico-reflexivo de la relación patrimonioidentidad- contexto sociocultural, a partir del dimensionamiento ontológico, gnoseológico y axiológico de los valorespatrimoniales, todo lo cual aporta recursos cognoscitivos y axiológicos válidos para favorecer la formación y desarrollo de un sujeto cultural que refrende su pertenencia identitaria.

  15. Seasonal dynamics of methane emissions from a subarctic fen in the Hudson Bay Lowlands

    Directory of Open Access Journals (Sweden)

    K. L. Hanis

    2013-03-01

    Full Text Available Ecosystem-scale methane (CH4 flux (FCH4 over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyzer in four years (2008–2011. Cumulative measured annual FCH4 (shoulder plus growing seasons ranged from 3.0 to 9.6 g CH4 m−2 yr−1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m−2 yr−1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near surface soil temperature at 5 cm most correlated across spring, fall, and the whole season. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but water table also exerted influence with FCH4 highest when water was 2–13 cm below and least when it was at or above the mean peat surface.

  16. Modeling thermodynamics of Fe-N phases; characterisation of e-Fe2N1-z

    DEFF Research Database (Denmark)

    Pekelharing, M.I.; Böttger, A.; Somers, Marcel A.J.

    1999-01-01

    In order to arrive at modeling the thermodynamics of Fe-N phases, including long-range (LRO) and short-range ordering (SRO) of the N atoms, it is important to understand the role of N interstitially dissolved in an Fe-host lattice. The crystal structure of -Fe2N1-z consists of an h.c.p. iron...... sublattice and a hexagonal nitrogen sublattice formed by octahedral interstices of the Fe sublattice [1]. Two ground-state structures have been proposed for the ordered arrangement of the N atoms on their own sublattice [1], which were shown to be thermodynamically favourable [2]: configuration A for Fe2N1...... investigated with X-ray diffraction (XRD) and Mössbauer spectroscopy. A thermodynamic model accounting for the two configurations of LRO of the N atoms [2,3] was fitted to the N-absorption isotherm at 723 K and resulted in the occupancies of the sites of the nitrogen sublattice. A miscibility gap between...

  17. The influence of degree of peat decomposition on phosphorus binding forms in fens

    Directory of Open Access Journals (Sweden)

    S. Jordan

    2007-10-01

    Full Text Available Re-wetting of drained fens can release phosphorus, introducing a eutrophication risk for associated aquatic ecosystems. Characterisation of the different forms of organic and inorganic bound phosphorus in the peat is an important step towards the development of tools for assessing the level of risk attached to individual re-wetting projects. In the work reported here, a sequential extraction (fractionation method was used to distinguish the following P binding forms:1. labile P, detected by NH4Cl extraction;2. redox-sensitive P, detected by Na2S2O4/NaHCO3 extraction;3. P adsorbed to metal oxides, detected by HCl extraction;4. P bound to humic substances, detected by NaOH extraction; and5. organic and refractory bound P, detected using H2SO4 and H2O2.Special attention was paid to the degree of decomposition (DPD of the peat, and metal concentrations were measured in selected fractions. Higher P concentrations were found in completely humified than in little humified peat for all fractions except the NH4Cl (labile P fraction, where P content increased as DPD decreased. As only 1% of total phosphorus (TP was present as labile P, the results indicate that the decisive horizons for nutrient release after re-wetting are those that are completely humified due to pedogenetic changes. The principal metal sorption partner for P was Fe.

  18. Leaf-litter microfungal community on poor fen plant debris in Torfy Lake area (Central Poland

    Directory of Open Access Journals (Sweden)

    Mateusz Wilk

    2014-06-01

    Full Text Available The purpose of this study was to initially evaluate the species diversity of microfungi growing on litter of 15 plant species occurring on the poor fen and neighbouring area of the Torfy Lake, Masovian voivodeship, Poland. The lake is located near the planned road investment (construction of the Warsaw southern express ring road S2. The place is biologically valuable as there are rare plant communities from Rhynchosporion albae alliance protected under the Habitats Directive adopted by the European Union. On the examined plant debris 73 taxa of fungi were recorded (3 basidiomycetes, 13 ascomycetes, 2 zygomycetes, 43 anamorphic ascomycetes, 12 unidentified. Two of them, Dicranidion sp. and Wentiomyces sp. are presented here as new to Poland. Among the plant species examined, the litter of Rhododendron tomentosum harbored the highest number of fungal taxa (16. The highest percents of substrate-specific microfungi (i.e. recorded only on one plant species was noted on R. tomentosum (81.3 %, and Pteridium aquilinum (75%. It is emphasized that the lake area should be protected not only because of rare plant community but also because of the uniqueness and diversity of mycobiota.

  19. High genetic diversity among strains of the unindustrialized lactic acid bacterium Carnobacterium maltaromaticum in dairy products as revealed by multilocus sequence typing.

    Science.gov (United States)

    Rahman, Abdur; Cailliez-Grimal, Catherine; Bontemps, Cyril; Payot, Sophie; Chaillou, Stéphane; Revol-Junelles, Anne-Marie; Borges, Frédéric

    2014-07-01

    Dairy products are colonized with three main classes of lactic acid bacteria (LAB): opportunistic bacteria, traditional starters, and industrial starters. Most of the population structure studies were previously performed with LAB species belonging to these three classes and give interesting knowledge about the population structure of LAB at the stage where they are already industrialized. However, these studies give little information about the population structure of LAB prior their use as an industrial starter. Carnobacterium maltaromaticum is a LAB colonizing diverse environments, including dairy products. Since this bacterium was discovered relatively recently, it is not yet commercialized as an industrial starter, which makes C. maltaromaticum an interesting model for the study of unindustrialized LAB population structure in dairy products. A multilocus sequence typing scheme based on an analysis of fragments of the genes dapE, ddlA, glpQ, ilvE, pyc, pyrE, and leuS was applied to a collection of 47 strains, including 28 strains isolated from dairy products. The scheme allowed detecting 36 sequence types with a discriminatory index of 0.98. The whole population was clustered in four deeply branched lineages, in which the dairy strains were spread. Moreover, the dairy strains could exhibit a high diversity within these lineages, leading to an overall dairy population with a diversity level as high as that of the nondairy population. These results are in agreement with the hypothesis according to which the industrialization of LAB leads to a diversity reduction in dairy products.

  20. Distinct abscisic acid signaling pathways for modulation of guard cell versus mesophyll cell potassium channels revealed by expression studies in Xenopus laevis oocytes

    Science.gov (United States)

    Sutton, F.; Paul, S. S.; Wang, X. Q.; Assmann, S. M.; Evans, M. L. (Principal Investigator)

    2000-01-01

    Regulation of guard cell ion transport by abscisic acid (ABA) and in particular ABA inhibition of a guard cell inward K(+) current (I(Kin)) is well documented. However, little is known concerning ABA effects on ion transport in other plant cell types. Here we applied patch clamp techniques to mesophyll cell protoplasts of fava bean (Vicia faba cv Long Pod) plants and demonstrated ABA inhibition of an outward K(+) current (I(Kout)). When mesophyll cell protoplast mRNA (mesophyll mRNA) was expressed in Xenopus laevis oocytes, I(Kout) was generated that displayed similar properties to I(Kout) observed from direct analysis of mesophyll cell protoplasts. I(Kout) expressed by mesophyll mRNA-injected oocytes was inhibited by ABA, indicating that the ABA signal transduction pathway observed in mesophyll cells was preserved in the frog oocytes. Co-injection of oocytes with guard cell protoplast mRNA and cRNA for KAT1, an inward K(+) channel expressed in guard cells, resulted in I(Kin) that was similarly inhibited by ABA. However, oocytes co-injected with mesophyll mRNA and KAT1 cRNA produced I(Kin) that was not inhibited by ABA. These results demonstrate that the mesophyll-encoded signaling mechanism could not substitute for the guard cell pathway. These findings indicate that mesophyll cells and guard cells use distinct and different receptor types and/or signal transduction pathways in ABA regulation of K(+) channels.

  1. Cell-free production of integral membrane aspartic acid proteases reveals zinc-dependent methyltransferase activity of the Pseudomonas aeruginosa prepilin peptidase PilD

    Science.gov (United States)

    Aly, Khaled A; Beebe, Emily T; Chan, Chi H; Goren, Michael A; Sepúlveda, Carolina; Makino, Shin-ichi; Fox, Brian G; Forest, Katrina T

    2013-01-01

    Integral membrane aspartic acid proteases are receiving growing recognition for their fundamental roles in cellular physiology of eukaryotes and prokaryotes, and may be medically important pharmaceutical targets. The Gram-negative Pseudomonas aeruginosa PilD and the archaeal Methanococcus voltae FlaK were synthesized in the presence of unilamellar liposomes in a cell-free translation system. Cosynthesis of PilD with its full-length substrate, PilA, or of FlaK with its full-length substrate, FlaB2, led to complete cleavage of the substrate signal peptides. Scaled-up synthesis of PilD, followed by solubilization in dodecyl-β-d-maltoside and chromatography, led to a pure enzyme that retained both of its known biochemical activities: cleavage of the PilA signal peptide and S-adenosyl methionine-dependent methylation of the mature pilin. X-ray fluorescence scans show for the first time that PilD is a zinc-binding protein. Zinc is required for the N-terminal methylation of the mature pilin, but not for signal peptide cleavage. Taken together, our work identifies the P. aeruginosa prepilin peptidase PilD as a zinc-dependent N-methyltransferase and provides a new platform for large-scale synthesis of PilD and other integral membrane proteases important for basic microbial physiology and virulence. PMID:23255525

  2. Mutagenesis of the aspartic acid ligands in human serum transferrin: lobe-lobe interaction and conformation as revealed by antibody, receptor-binding and iron-release studies.

    Science.gov (United States)

    Mason, A; He, Q Y; Tam, B; MacGillivray, R A; Woodworth, R

    1998-01-01

    Recombinant non-glycosylated human serum transferrin and mutants in which the liganding aspartic acid (D) in one or both lobes was changed to a serine residue (S) were produced in a mammalian cell system and purified from the tissue culture media. Significant downfield shifts of 20, 30, and 45 nm in the absorption maxima were found for the D63S-hTF, D392S-hTF and the double mutant, D63S/D392S-hTF when compared to wild-type hTF. A monoclonal antibody to a sequential epitope in the C-lobe of hTF reported affinity differences between the apo- and iron-forms of each mutant and the control. Cell-binding studies performed under the same buffer conditions used for the antibody work clearly showed that the mutated lobe(s) had an open cleft. It is not clear whether the receptor itself may play a role in promoting the open conformation or whether the iron remains in the cleft. PMID:9461487

  3. Transcriptome Analysis Reveals the Mechanism Underlying the Production of a High Quantity of Chlorogenic Acid in Young Leaves of Lonicera macranthoides Hand.-Mazz.

    Science.gov (United States)

    Chen, Zexiong; Tang, Ning; You, Yuming; Lan, Jianbin; Liu, Yiqing; Li, Zhengguo

    2015-01-01

    Lonicera macranthoides Hand.-Mazz (L. macranthoides) is a medicinal herb that is widely distributed in southern China. The biosynthetic and metabolic pathways for a core secondary metabolite in L. macranthoides, chlorogenic acid (CGA), have been elucidated in many species. However, the mechanisms of CGA biosynthesis and the related gene regulatory network in L. macranthoides are still not well understood. In this study, CGA content was quantified by high performance liquid chromatography (HPLC), and CGA levels differed significantly among three tissues; specifically, the CGA content in young leaves (YL) was greater than that in young stems (YS), which was greater than that in mature flowers (MF). Transcriptome analysis of L. macranthoides yielded a total of 53,533,014 clean reads (average length 90 bp) and 76,453 unigenes (average length 703 bp). A total of 3,767 unigenes were involved in biosynthesis pathways of secondary metabolites. Of these unigenes, 80 were possibly related to CGA biosynthesis. Furthermore, differentially expressed genes (DEGs) were screened in different tissues including YL, MF and YS. In these tissues, 24 DEGs were found to be associated with CGA biosynthesis, including six phenylalanine ammonia lyase (PAL) genes, six 4-coumarate coenzyme A ligase (4CL) genes, four cinnamate 4-Hydroxylase (C4H) genes, seven hydroxycinnamoyl transferase/hydroxycinnamoyl-CoA quinate transferase HCT/HQT genes and one coumarate 3-hydroxylase (C3H) gene.These results further the understanding of CGA biosynthesis and the related regulatory network in L. macranthoides.

  4. Transcriptome Analysis Reveals the Mechanism Underlying the Production of a High Quantity of Chlorogenic Acid in Young Leaves of Lonicera macranthoides Hand.-Mazz.

    Directory of Open Access Journals (Sweden)

    Zexiong Chen

    Full Text Available Lonicera macranthoides Hand.-Mazz (L. macranthoides is a medicinal herb that is widely distributed in southern China. The biosynthetic and metabolic pathways for a core secondary metabolite in L. macranthoides, chlorogenic acid (CGA, have been elucidated in many species. However, the mechanisms of CGA biosynthesis and the related gene regulatory network in L. macranthoides are still not well understood. In this study, CGA content was quantified by high performance liquid chromatography (HPLC, and CGA levels differed significantly among three tissues; specifically, the CGA content in young leaves (YL was greater than that in young stems (YS, which was greater than that in mature flowers (MF. Transcriptome analysis of L. macranthoides yielded a total of 53,533,014 clean reads (average length 90 bp and 76,453 unigenes (average length 703 bp. A total of 3,767 unigenes were involved in biosynthesis pathways of secondary metabolites. Of these unigenes, 80 were possibly related to CGA biosynthesis. Furthermore, differentially expressed genes (DEGs were screened in different tissues including YL, MF and YS. In these tissues, 24 DEGs were found to be associated with CGA biosynthesis, including six phenylalanine ammonia lyase (PAL genes, six 4-coumarate coenzyme A ligase (4CL genes, four cinnamate 4-Hydroxylase (C4H genes, seven hydroxycinnamoyl transferase/hydroxycinnamoyl-CoA quinate transferase HCT/HQT genes and one coumarate 3-hydroxylase (C3H gene.These results further the understanding of CGA biosynthesis and the related regulatory network in L. macranthoides.

  5. Differences between main-channel and off-channel food webs in the upper Mississippi River revealed by fatty acid profiles of consumers

    Science.gov (United States)

    Larson, James H.; Bartsch, Michelle; Gutreuter, Steve; Knights, Brent C.; Bartsch, Lynn; Richardson, William B.; Vallazza, Jonathan M.; Arts, Michael T.

    2015-01-01

    Large river systems are often thought to contain a mosaic of patches with different habitat characteristics driven by differences in flow and mixing environments. Off-channel habitats (e.g., backwater areas, secondary channels) can become semi-isolated from main-channel water inputs, leading to the development of distinct biogeochemical environments. Observations of adult bluegill (Lepomis macrochirus) in the main channel of the Mississippi River led to speculation that the main channel offered superior food resources relative to off-channel areas. One important aspect of food quality is the quantity and composition of polyunsaturated fatty acids (PUFA). We sampled consumers from main-channel and backwater habitats to determine whether they differed in PUFA content. Main-channel individuals for relatively immobile species (young-of-year bluegill, zebra mussels [Dreissena polymorpha], and plain pocketbook mussels [Lampsilis cardium]) had significantly greater PUFA content than off-channel individuals. No difference in PUFA was observed for the more mobile gizzard shad (Dorsoma cepedianum), which may move between main-channel and off-channel habitats even at early life-history stages. As off-channel habitats become isolated from main-channel waters, flow and water column nitrogen decrease, potentially improving conditions for nitrogen-fixing cyanobacteria and vascular plants that, in turn, have low PUFA content. We conclude that main-channel food webs of the upper Mississippi River provide higher quality food resources for some riverine consumers as compared to food webs in off-channel habitats.

  6. Proteomic analysis reveals differences in tolerance to acid rain in two broad-leaf tree species, Liquidambar formosana and Schima superba.

    Science.gov (United States)

    Chen, Juan; Hu, Wen-Jun; Wang, Chao; Liu, Ting-Wu; Chalifour, Annie; Chen, Juan; Shen, Zhi-Jun; Liu, Xiang; Wang, Wen-Hua; Zheng, Hai-Lei

    2014-01-01

    Acid rain (AR) is a serious environmental issue inducing harmful impacts on plant growth and development. It has been reported that Liquidambar formosana, considered as an AR-sensitive tree species, was largely injured by AR, compared with Schima superba, an AR-tolerant tree species. To clarify the different responses of these two species to AR, a comparative proteomic analysis was conducted in this study. More than 1000 protein spots were reproducibly detected on two-dimensional electrophoresis gels. Among them, 74 protein spots from L. formosana gels and 34 protein spots from S. superba gels showed significant changes in their abundances under AR stress. In both L. formosana and S. superba, the majority proteins with more than 2 fold changes were involved in photosynthesis and energy production, followed by material metabolism, stress and defense, transcription, post-translational and modification, and signal transduction. In contrast with L. formosana, no hormone response-related protein was found in S. superba. Moreover, the changes of proteins involved in photosynthesis, starch synthesis, and translation were distinctly different between L. formosana and S. superba. Protein expression analysis of three proteins (ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit, ascorbate peroxidase and glutathione-S-transferase) by Western blot was well correlated with the results of proteomics. In conclusion, our study provides new insights into AR stress responses in woody plants and clarifies the differences in strategies to cope with AR between L. formosana and S. superba.

  7. Structural and enzymatic analysis of TarM glycosyltransferase from Staphylococcus aureus reveals an oligomeric protein specific for the glycosylation of wall teichoic acid.

    Science.gov (United States)

    Koç, Cengiz; Gerlach, David; Beck, Sebastian; Peschel, Andreas; Xia, Guoqing; Stehle, Thilo

    2015-04-10

    Anionic glycopolymers known as wall teichoic acids (WTAs) functionalize the peptidoglycan layers of many Gram-positive bacteria. WTAs play central roles in many fundamental aspects of bacterial physiology, and they are important determinants of pathogenesis and antibiotic resistance. A number of enzymes that glycosylate WTA in Staphylococcus aureus have recently been identified. Among these is the glycosyltransferase TarM, a component of the WTA de novo biosynthesis pathway. TarM performs the synthesis of α-O-N-acetylglycosylated poly-5'-phosphoribitol in the WTA structure. We have solved the crystal structure of TarM at 2.4 Å resolution, and we have also determined a structure of the enzyme in complex with its substrate UDP-GlcNAc at 2.8 Å resolution. The protein assembles into a propeller-like homotrimer in which each blade contains a GT-B-type glycosyltransferase domain with a typical Rossmann fold. The enzymatic reaction retains the stereochemistry of the anomeric center of the transferred GlcNAc-moiety on the polyribitol backbone. TarM assembles into a trimer using a novel trimerization domain, here termed the HUB domain. Structure-guided mutagenesis experiments of TarM identify residues critical for enzyme activity, assign a putative role for the HUB in TarM function, and allow us to propose a likely reaction mechanism.

  8. Water level, vegetation composition, and plant productivity explain greenhouse gas fluxes in temperate cutover fens after inundation

    Science.gov (United States)

    Minke, Merten; Augustin, Jürgen; Burlo, Andrei; Yarmashuk, Tatsiana; Chuvashova, Hanna; Thiele, Annett; Freibauer, Annette; Tikhonov, Vitalij; Hoffmann, Mathias

    2016-07-01

    Peat extraction leaves a land surface with a strong relief of deep cutover areas and higher ridges. Rewetting inundates the deep parts, while less deeply extracted zones remain at or above the water level. In temperate fens the flooded areas are colonized by helophytes such as Eriophorum angustifolium, Carex spp., Typha latifolia or Phragmites australis dependent on water depth. Reeds of Typha and Phragmites are reported as large sources of methane, but data on net CO2 uptake are contradictory for Typha and rare for Phragmites. Here, we analyze the effect of vegetation, water level and nutrient conditions on greenhouse gas (GHG) emissions for representative vegetation types along water level gradients at two rewetted cutover fens (mesotrophic and eutrophic) in Belarus. Greenhouse gas emissions were measured campaign-wise with manual chambers every 2 to 4 weeks for 2 years and interpolated by modelling. All sites had negligible nitrous oxide exchange rates. Most sites were carbon sinks and small GHG sources. Methane emissions generally increased with net ecosystem CO2 uptake. Mesotrophic small sedge reeds with water table around the land surface were small GHG sources in the range of 2.3 to 4.2 t CO2 eq. ha-1 yr-1. Eutrophic tall sedge - Typha latifolia reeds on newly formed floating mats were substantial net GHG emitters in the range of 25.1 to 39.1 t CO2 eq. ha-1 yr. They represent transient vegetation stages. Phragmites reeds ranged between -1.7 to 4.2 t CO2 eq. ha-1 yr-1 with an overall mean GHG emission of 1.3 t CO2 eq. ha-1 yr-1. The annual CO2 balance was best explained by vegetation biomass, which includes the role of vegetation composition and species. Methane emissions were obviously driven by biological activity of vegetation and soil organisms. Shallow flooding of cutover temperate fens is a suitable measure to arrive at low GHG emissions. Phragmites australis establishment should be promoted in deeper flooded areas and will lead to moderate, but

  9. The hsp 16 gene of the probiotic Lactobacillus acidophilus is differently regulated by salt, high temperature and acidic stresses, as revealed by reverse transcription quantitative PCR (qRT-PCR) analysis.

    Science.gov (United States)

    Capozzi, Vittorio; Arena, Mattia Pia; Crisetti, Elisabetta; Spano, Giuseppe; Fiocco, Daniela

    2011-01-01

    Small heat shock proteins (sHsps) are ubiquitous conserved chaperone-like proteins involved in cellular proteins protection under stressful conditions. In this study, a reverse transcription quantitative PCR (RT-qPCR) procedure was developed and used to quantify the transcript level of a small heat shock gene (shs) in the probiotic bacterium Lactobacillus acidophilus NCFM, under stress conditions such as heat (45 °C and 53 °C), bile (0.3% w/v), hyperosmosis (1 M and 2.5 M NaCl), and low pH value (pH 4). The shs gene of L. acidophilus NCFM was induced by salt, high temperature and acidic stress, while repression was observed upon bile stress. Analysis of the 5' noncoding region of the hsp16 gene reveals the presence of an inverted repeat (IR) sequence (TTAGCACTC-N9-GAGTGCTAA) homologue to the controlling IR of chaperone expression (CIRCE) elements found in the upstream regulatory region of Gram-positive heat shock operons, suggesting that the hsp16 gene of L. acidophilus might be transcriptionally controlled by HrcA. In addition, the alignment of several small heat shock proteins identified so far in lactic acid bacteria, reveals that the Hsp16 of L. acidophilus exhibits a strong evolutionary relationship with members of the Lactobacillus acidophilus group.

  10. The hsp 16 Gene of the Probiotic Lactobacillus acidophilus Is Differently Regulated by Salt, High Temperature and Acidic Stresses, as Revealed by Reverse Transcription Quantitative PCR (qRT-PCR Analysis

    Directory of Open Access Journals (Sweden)

    Daniela Fiocco

    2011-08-01

    Full Text Available Small heat shock proteins (sHsps are ubiquitous conserved chaperone-like proteins involved in cellular proteins protection under stressful conditions. In this study, a reverse transcription quantitative PCR (RT-qPCR procedure was developed and used to quantify the transcript level of a small heat shock gene (shs in the probiotic bacterium Lactobacillus acidophilus NCFM, under stress conditions such as heat (45 °C and 53 °C, bile (0.3% w/v, hyperosmosis (1 M and 2.5 M NaCl, and low pH value (pH 4. The shs gene of L. acidophilus NCFM was induced by salt, high temperature and acidic stress, while repression was observed upon bile stress. Analysis of the 5' noncoding region of the hsp16 gene reveals the presence of an inverted repeat (IR sequence (TTAGCACTC-N9-GAGTGCTAA homologue to the controlling IR of chaperone expression (CIRCE elements found in the upstream regulatory region of Gram-positive heat shock operons, suggesting that the hsp16 gene of L. acidophilus might be transcriptionally controlled by HrcA. In addition, the alignment of several small heat shock proteins identified so far in lactic acid bacteria, reveals that the Hsp16 of L. acidophilus exhibits a strong evolutionary relationship with members of the Lactobacillus acidophilus group.

  11. Label-Free LC-MS Profiling of Skeletal Muscle Reveals Heart-Type Fatty Acid Binding Protein as a Candidate Biomarker of Aerobic Capacity

    Directory of Open Access Journals (Sweden)

    Zulezwan A. Malik

    2013-12-01

    Full Text Available Two-dimensional gel electrophoresis provides robust comparative analysis of skeletal muscle, but this technique is laborious and limited by its inability to resolve all proteins. In contrast, orthogonal separation by SDS-PAGE and reverse-phase liquid chromatography (RPLC coupled to mass spectrometry (MS affords deep mining of the muscle proteome, but differential analysis between samples is challenging due to the greater level of fractionation and the complexities of quantifying proteins based on the abundances of their tryptic peptides. Here we report simple, semi-automated and time efficient (i.e., 3 h per sample proteome profiling of skeletal muscle by 1-dimensional RPLC electrospray ionisation tandem MS. Solei were analysed from rats (n = 5, in each group bred as either high- or low-capacity runners (HCR and LCR, respectively that exhibited a 6.4-fold difference (1,625 ± 112 m vs. 252 ± 43 m, p < 0.0001 in running capacity during a standardized treadmill test. Soluble muscle proteins were extracted, digested with trypsin and individual biological replicates (50 ng of tryptic peptides subjected to LC-MS profiling. Proteins were identified by triplicate LC-MS/MS analysis of a pooled sample of each biological replicate. Differential expression profiling was performed on relative abundances (RA of parent ions, which spanned three orders of magnitude. In total, 207 proteins were analysed, which encompassed almost all enzymes of the major metabolic pathways in skeletal muscle. The most abundant protein detected was type I myosin heavy chain (RA = 5,843 ± 897 and the least abundant protein detected was heat shock 70 kDa protein (RA = 2 ± 0.5. Sixteen proteins were significantly (p < 0.05 more abundant in HCR muscle and hierarchal clustering of the profiling data highlighted two protein subgroups, which encompassed proteins associated with either the respiratory chain or fatty acid oxidation. Heart-type fatty acid binding protein (FABPH was 1

  12. Intracisternal delivery of NFkappaB-inducible scAAV2/9 reveals locoregional neuroinflammation induced by systemic kainic acid treatment.

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    Olivier eBockstael

    2014-12-01

    Full Text Available We have previously demonstrated disease-dependent gene delivery in the brain using an AAV vector responding to NFB activation as a probe for inflammatory responses. This vector, injected focally in the parenchyma prior to a systemic kainic acid (KA injection mediated inducible transgene expression in the hippocampus but not in the cerebellum, regions respectively known to be affected or not by the pathology. However, such a focal approach relies on previous knowledge of the model parameters and does not allow to predict the whole brain response to the disease. Global brain gene delivery would allow to predict the regional distribution of the pathology as well as to deliver therapeutic factors in all affected brain regions.We show that self-complementary AAV2/9 (scAAV2/9 delivery in the adult rat cisterna magna allows a widespread but not homogenous transduction of the brain. Indeed, superficial regions, i.e. cortex, hippocampus and cerebellum were more efficiently transduced than deeper regions, such as striatum, and substantia nigra. These data suggest that viral particles penetration from the cerebrospinal fluid (CSF into the brain is a limiting factor. Interestingly, AAV2/9-2YF a rationally-designed capsid mutant (affecting surface tyrosines increased gene transfer efficiency approx. 5-fold. Neurons, astrocytes and oligodendrocytes, but not microglia, were transduced in varying proportions depending on the brain region and the type of capsid.Finally, after a single intracisternal injection of scAAV2/9-2YF using the NFB-inducible promoter, KA treatment induced transgene expression in the hippocampus and cortex but not in the cerebellum, corresponding to the expression of the CD11b marker of microglial activation.These data support the use of disease-inducible vectors administered in the cisterna magna as a tool to characterize the brain pathology in systemic drug-induced or transgenic disease models. However, further improvements are

  13. Enzymatic degradation processes of lamellar crystals in thin films for poly[(R)-3-hydroxybutyric acid] and its copolymers revealed by real-time atomic force microscopy.

    Science.gov (United States)

    Numata, Keiji; Hirota, Takuya; Kikkawa, Yoshihiro; Tsuge, Takeharu; Iwata, Tadahisa; Abe, Hideki; Doi, Yoshiharu

    2004-01-01

    Enzymatic degradation processes of flat-on lamellar crystals in melt-crystallized thin films of poly[(R)-3-hydroxybutyric acid] (P(3HB)) and its copolymers were characterized by real-time atomic force microscopy (AFM) in a phosphate buffer solution containing PHB depolymerase from Ralstonia pickettii T1. Fiberlike crystals with regular intervals were generated along the crystallographic a axis at the end of lamellar crystals during the enzymatic degradation. The morphologies and sizes of the fiberlike crystals were markedly dependent on the compositions of comonomer units in the polyesters. Length, width, interval, and thickness of the fiberlike crystals after the enzymatic degradation for 2 h were measured by AFM, and the dimensions were related to the solid-state structures of P(3HB) and its copolymers. The width and thickness decreased at the tip of fiberlike crystals, indicating that the enzymatic degradation of crystals takes place not only along the a axis but also along the b and c axes. These results from AFM measurement were compared with the data on crystal size by wide-angle X-ray diffraction, and on lamellar thickness and long period by small-angle X-ray scattering. In addition, the enzymatic erosion rate of flat-on lamellar crystals along the a axis was measured from real-time AFM height images. A schematic glacier model for the enzymatic degradation of flat-on lamellar crystals of P(3HB) by PHB depolymerase has been proposed on the basis of the AFM observations.

  14. Agonist-dependent endocytosis of γ-aminobutyric acid type A (GABAA) receptors revealed by a γ2(R43Q) epilepsy mutation.

    Science.gov (United States)

    Chaumont, Severine; André, Caroline; Perrais, David; Boué-Grabot, Eric; Taly, Antoine; Garret, Maurice

    2013-09-27

    GABA-gated chloride channels (GABAARs) trafficking is involved in the regulation of fast inhibitory transmission. Here, we took advantage of a γ2(R43Q) subunit mutation linked to epilepsy in humans that considerably reduces the number of GABAARs on the cell surface to better understand the trafficking of GABAARs. Using recombinant expression in cultured rat hippocampal neurons and COS-7 cells, we showed that receptors containing γ2(R43Q) were addressed to the cell membrane but underwent clathrin-mediated dynamin-dependent endocytosis. The γ2(R43Q)-dependent endocytosis was reduced by GABAAR antagonists. These data, in addition to a new homology model, suggested that a conformational change in the extracellular domain of γ2(R43Q)-containing GABAARs increased their internalization. This led us to show that endogenous and recombinant wild-type GABAAR endocytosis in both cultured neurons and COS-7 cells can be amplified by their agonists. These findings revealed not only a direct relationship between endocytosis of GABAARs and a genetic neurological disorder but also that trafficking of these receptors can be modulated by their agonist.

  15. Análisis del downsizing (reducción de plantilla como fenómeno psicosocial

    Directory of Open Access Journals (Sweden)

    CRISTÓBAL JIMÉNEZ JIMÉNEZ

    2005-01-01

    Full Text Available En este trabajo se analiza el downsizing como fenómeno recurrente y de gran actualidad en el mundo de los negocios y de las organizaciones, delimitando su concepto, señalando su incidencia y destacando sus principales características. Después de enmarcar el downsizing en el ámbito específico del Estrés Laboral, se argumenta la importancia y conveniencia de considerarlo, de pleno derecho, como fenómeno psico-socio-laboral, señalando algunas implicaciones de interés para el ámbito de los Recursos Humanos en el marco de la Prevención de Riesgos Laborales.

  16. Marketing aplicado a los fenómenos culturales: la digitalización en el festival de cine

    OpenAIRE

    Sanz de la Serna, Gemma

    2016-01-01

    El ámbito amplio de trabajo de la presente tesis doctoral es el marketing aplicado a los fenómenos culturales. Y se hacía preciso concretarlo en un campo de acción más estricto y específico; por eso hemos elegido el fenómeno cultural del cine y, dentro de él, el festival de cine; y todo ello en el campo concreto de la digitalización. Lo digital ha cambiado no sólo la forma en la que consumimos, trabajamos o nos relacionamos socialmente; también ha transformado cómo nos entretenemos. No es de ...

  17. El fenómeno de "El Niño" y la Oscilación Sur (ENSO)

    OpenAIRE

    Zambrano, E.

    1986-01-01

    Este evento no fue pronosticado y no fue reconocido como "El Niño" hasta que estuvo bien desarrollado, así mismo su evolución y duración no fue anticipada. Se ha desarrollado una considerable investigación estimulada por la ocurrencia de este evento, lo cual pone de manifiesto el incompleto estado de nuestro conocimiento sobre el fenómeno de "El Niño".

  18. Reclutamiento de niños y niñas: fenómeno invisibilizado, crimen manifiesto

    Directory of Open Access Journals (Sweden)

    Verónica Hinestroza-Arenas

    2008-11-01

    Full Text Available En los últimos 15 años la comunidad internacional ha dirigido esfuerzos importantes para llamar la atención sobre las dimensiones mundiales del fenómeno del reclutamiento de niños y niñas y su uso en hostilidades. Dichos esfuerzos se han materializado en convenciones, protocolos y principios para la protección de la infancia y la penalización de la

  19. Reclutamiento de niños y niñas: fenómeno invisibilizado, crimen manifiesto

    OpenAIRE

    Verónica Hinestroza-Arenas

    2008-01-01

    En los últimos 15 años la comunidad internacional ha dirigido esfuerzos importantes para llamar la atención sobre las dimensiones mundiales del fenómeno del reclutamiento de niños y niñas y su uso en hostilidades. Dichos esfuerzos se han materializado en convenciones, protocolos y principios para la protección de la infancia y la penalización de la

  20. Wetlands and the Water Framework Directive : key challenges for achieving good ecological status at the Anglesey and LLyn Fens SACs

    OpenAIRE

    Farr, Gareth; Whiteman, Mark; Jones, Peter; Breen, Rachel

    2013-01-01

    The Water Framework Directive (WFD) requires assessment of water quality and quantity in groundwater bodies that are hydrologically linked to designated wetlands. The Anglesey and Llŷn Fens face chemical (e.g. nitrate) and quantitative (e.g. historic drainage) groundwater pressures. Hydrogeologists and ecologists have successfully worked together during the WFD classification process and impacts from diffuse nutrients have resulted in ‘poor’ chemical status for the surrounding Carboniferous ...

  1. Extracción de compuestos fenólicos de la uva al vino. Papel de los enzimas de maceración

    OpenAIRE

    2008-01-01

    La extracción de los compuestos fenólicos, responsables de ciertas características de color de los vinos, va a depender entre otros, de la degradación de la pared celular, por lo que el uso de enzimas pectolíticos podría ser una técnica adecuada para obtener vinos con mayor carga polifenólica. Los resultados mostraron que la extracción de los compuestos fenólicos durante la maceración es incompleta. Además, estudiando la extractabilidad de los compuestos fenólicos en diferentes variedade...

  2. In vitro anti-coxsackievirus B3 effect of ethyl acetate extract of Tian-hua-fen

    Institute of Scientific and Technical Information of China (English)

    Zhen-Hong Li; Bao-Ming Nie; Hong Chen; Shu-Yun Chen; Ping He; Yang Lu; Xiao-Kui Guo; Jing-Xing Liu

    2004-01-01

    AIM: To investigation the anti-coxsackievirus B3 (CVB3m)effect of the ethyl acetate extract of Tian-hua-fen on HeLa cells infected with CVB3m.METHODS: HeLa cells were infected with CVB3m and the cytopathic effects (CPE) were observed through light microscope and crystal violet staining on 96-well plate and A600 was detected using spectrophotometer. The protective effect of the extract to HeLa cells and the mechanism of the effect were also evaluated through the change of CPE and value of A600.RESULTS: The extract had some toxicity to HeLa cells at a higher concentration while had a marked inhibitory effect on cell pathological changes at a lower concentration.Consistent results were got through these two methods.We also investigated the mechanism of its anti-CVB3m effect and the results indicated that the extract represented an inhibitory effect through all the processes of CVB3m attachment, entry, biosynthesis and assemble in cells.CONCLUSION: The results demonstrate that the ethyl acetate extract of Tian-hua-fen has a significant protective effect on HeLa cells infected with CVB3m in a dose-dependent manner and this effect exists through the process of CVB3m attachment, entry, biosynthesis and assemble in cells,suggesting that the ethyl acetate extract of Tian-hua-fen can be developed as an anti-virus agent.

  3. A cryptic targeting signal creates a mitochondrial FEN1 isoform with tailed R-Loop binding properties.

    Directory of Open Access Journals (Sweden)

    Lawrence Kazak

    Full Text Available A growing number of DNA transacting proteins is found in the nucleus and in mitochondria, including the DNA repair and replication protein Flap endonuclease 1, FEN1. Here we show a truncated FEN1 isoform is generated by alternative translation initiation, exposing a mitochondrial targeting signal. The shortened form of FEN1, which we term FENMIT, localizes to mitochondria, based on import into isolated organelles, immunocytochemistry and subcellular fractionation. In vitro FENMIT binds to flap structures containing a 5' RNA flap, and prefers such substrates to single-stranded RNA. FENMIT can also bind to R-loops, and to a lesser extent to D-loops. Exposing human cells to ethidium bromide results in the generation of RNA/DNA hybrids near the origin of mitochondrial DNA replication. FENMIT is recruited to the DNA under these conditions, and is released by RNase treatment. Moreover, high levels of recombinant FENMIT expression inhibit mtDNA replication, following ethidium bromide treatment. These findings suggest FENMIT interacts with RNA/DNA hybrids in mitochondrial DNA, such as those found at the origin of replication.

  4. Recent rates of carbon accumulation in montane fens ofYosemite National Park, California, U.S.A.

    Science.gov (United States)

    Drexler, Judith; Fuller, Christopher C.; Orlando, James; Moore, Peggy E.

    2016-01-01

    Little is known about recent rates of carbon storage in montane peatlands, particularly in the western United States. Here we report on recent rates of carbon accumulation (past 50 to 100 years) in montane groundwater-fed peatlands (fens) of Yosemite National Park in central California, U.S.A. Peat cores were collected at three sites ranging in elevation from 2070 to 2500 m. Core sections were analyzed for bulk density, % organic carbon, and 210Pb activities for dating purposes. Organic carbon densities ranged from 0.026 to 0.065 g C cm-3. Mean vertical accretion rates estimated using210Pb over the 50-year period from ∼1960 to 2011 and the 100-year period from ∼1910 to 2011 were 0.28 (standard deviation = ±0.09) and 0.18 (±-0.04) cm yr-1, respectively. Mean carbon accumulation rates over the 50- and 100-year periods were 95.4 (±25.4) and 74.7 (±17.2) g C m-2 yr-1, respectively. Such rates are similar to recent rates of carbon accumulation in rich fens in western Canada, but more studies are needed to definitively establish both the similarities and differences in peat formation between boreal and temperate montane fens.

  5. The Overexpression of FEN1 and RAD54B May Act as Independent Prognostic Factors of Lung Adenocarcinoma.

    Directory of Open Access Journals (Sweden)

    Jau-Chung Hwang

    Full Text Available Synthetic lethality arises when a combination of mutations in two or more genes leads to cell death. However, the prognostic role of concordant overexpression of synthetic lethality genes in protein level rather than a combination of mutations is not clear. In this study, we explore the prognostic role of combined overexpression of paired genes in lung adenocarcinoma. We used immunohistochemical staining to investigate 24 paired genes in 93 lung adenocarcinoma patients and Kaplan-Meier analysis and Cox proportional hazards models to evaluate their prognostic roles. Among 24 paired genes, only FEN1 (Flap endonuclease 1 and RAD54B (RAD54 homolog B were overexpressed in lung adenocarcinoma patients with poor prognosis. Patients with expression of both FEN1 and RAD54B were prone to have advanced nodal involvement and significantly poor prognosis (HR = 2.35, P = 0.0230. These results suggest that intensive follow up and targeted therapy might improve clinical outcome for patients who show expression of both FEN1 and RAD54B.

  6. Fenômeno de Lúcio fatal: relato de caso de autópsia

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    Fernando Peixoto Ferraz de Campos

    2012-08-01

    Full Text Available A Hanseníase de Lúcio e Alvarado, considerada a forma mais anérgica do espectro imunológico hansênico, caracteriza-se por espessamento e infiltração difusa, com alopecia difusa e total, associado a comprometimento sistêmico importante.Nessepolo da doença, os bacilos são numerosos em todos os tecidos. A alta carga bacilar no endotélio e o desenvolvimento de vasculite leucocitoclástica de pequenos e médiosvasos resultam em extensas áreas necrótico-ulcerativas, denominada fenômeno de Lúcio. Apresentamos a seguir um caso de autópsia de um paciente do sexo feminino que apresentava lesões cutâneas, há 20 anos, sem diagnóstico definido, com piora dos sintomas e aparecimento de novas lesões, há 3 semanas da internação.Devido à gravidade da doença e às conseqüentes complicações infecciosas, a paciente apresentou evolução fatal. A avaliação anátomo patológica mostrou comprometimento sistêmico por lepra e múltiplas úlceras cutâneas. As lesões cutâneas eram secundárias a vasculite leucocitoclástica e oclusão vascular, consistente com Reação de Lucio.

  7. Evaluating governance for sustainable development - Insights from experiences in the Dutch fen landscape.

    Science.gov (United States)

    den Uyl, Roos M; Driessen, Peter P J

    2015-11-01

    Prominent strands of discussion in the literature on governance for sustainable development debate how change can be induced to enhance sustainability, and how to evaluate the interventions aimed at prompting such change. Strikingly, there are few contributions about how prominent ideas of inducing change deal with multiple governance criteria for pursuing sustainable development. Moreover, the way ideas about inducing change relate to criteria of governance for sustainable development is not yet studied in an empirical context. This paper therefore comparatively analyses how three prominent modes of sustainable development governance - adaptive management, transition management and payments for environmental services - relate to a set of five prominent criteria reported in the literature, namely: equity, democracy, legitimacy, the handling of scale issues and the handling of uncertainty issues. It finds that the academic debates on these three modes address these criteria with varying attention and rather fragmented, while in the empirical setting of the Dutch fen landscape several aspects relating to the studied criteria were present and substantially influenced the functioning of the three modes of sustainable development. Together, the analysis of the literature debate and the empirical data are able to show that a narrow evaluation perspective may fail to diagnose and capture relevant struggles and complexities coming along with governance for sustainable development relevant issues. The study shows that in order to advance our understanding of governance for sustainable development, it is indeed important to include multiple criteria in studying these modes. Moreover, the study shows the importance of including empirical experiences which manifest when different modes for sustainable development are applied in real-world settings.

  8. Carbon dioxide fluxes at an intensively cultivated temperate lowland peatland in the East Anglian Fens, UK

    Directory of Open Access Journals (Sweden)

    R. Morrison

    2013-03-01

    Full Text Available This study reports the first recorded CO2 flux measurements of a drained and intensively cultivated lowland peatland in the East Anglian Fens (UK using the eddy covariance technique. Measurements were made over a complete lettuce crop rotation and a subsequent fallow period. Maximum average daytime CO2 uptake and nocturnal loss rates were −10.39 and 7.63 μmol CO2 m−2 s−1, respectively. Daily CO2 budgets ranged from a net loss of 4.7 to a small net uptake of −1.23 g CO2-C m−2 d−1. Total vertical land/atmosphere CO2 losses were estimated at 227.11 ± 46.5 g CO2-C m−2 for a~120 day measurement period. Losses over a sixty day interval between field preparation and disking of the field at the end of the crop cycle were 74.22 ± 18.8 g CO2-C m−2. The site lost 152.89 ± 30.6 g CO2-C m−2 d−1 during a sixty day fallow period. Net ecosystem production was estimated at 117.72 ± 18.8 g CO2-C m−2 during the crop cycle and 270.61 ± 46.49 g CO2-C m−2 for the entire measurement period when harvested crop exports were accounted for. These results represent the first micrometeorological measurements obtained over degraded lowland peatland in Britain, and illustrate the scale of CO2 losses associated with agricultural production on temperate organic soils.

  9. Eutrophication triggers contrasting multilevel feedbacks on litter accumulation and decomposition in fens.

    Science.gov (United States)

    Emsens, W-J; Aggenbach, C J S; Grootjans, A P; Nfor, E E; Schoelynck, J; Struyf, E; van Diggelen, R

    2016-10-01

    Eutrophication is a major threat for the persistence of nutrient-poor fens, as multilevel feedbacks on decomposition rates could trigger carbon loss and increase nutrient cycling. Here, we experimentally investigate the effects of macronutrient (NPK) enrichment on litter quality of six species of sedge (Carex sp.), which we relate to litter decomposition rates in a nutrient-poor and nutrient-rich environment. Our research focused on four levels: we examined how eutrophication alters (1) fresh litter production ("productivity shift"), (2) litter stoichiometry within the same species ("intraspecific shift"), (3) overall litter stoichiometry of the vegetation under the prediction that low-competitive species are outcompeted by fast-growing competitors ("interspecific shift"), and (4) litter decomposition rates due to an altered external environment (e.g., shifts in microbial activity; "exogenous shift"). Eutrophication triggered a strong increase in fresh litter production. Moreover, individuals of the same species produced litter with lower C:N and C:P ratios, higher K contents, and lower lignin, Ca and Mg contents (intraspecific shift), which increased litter decomposability. In addition, species typical for eutrophic conditions produced more easily degradable litter than did species typical for nutrient-poor conditions (interspecific shift). However, the effects of nutrient loading of the external environment (exogenous shift) were contradictory. Here, interactions between litter type and ambient nutrient level indicate that the (exogenous) effects of eutrophication on litter decomposition rates are strongly dependent of litter quality. Moreover, parameters of litter quality only correlated with decomposition rates for litter incubated in nutrient-poor environments, but not in eutrophic environments. This suggests that rates of litter decomposition can be uncoupled from litter stoichiometry under eutrophic conditions. In conclusion, our results show that

  10. Atividade antioxidante e teor de fenólicos totais em hortaliças orgânicas e convencionais Antioxidant activity and phenolic content in organic and conventional vegetables

    Directory of Open Access Journals (Sweden)

    Kettelin Aparecida Arbos

    2010-06-01

    Full Text Available Considerando que os consumidores estão mais conscientes com a sua saúde e mais preocupados com as condições ambientais, verifica-se uma crescente demanda por alimentos orgânicos. O objetivo deste estudo foi comparar a atividade antioxidante e o teor de fenólicos totais entre alface, rúcula e almeirão de cultivos orgânico e convencional, plantados em uma mesma horta. A atividade antioxidante dos extratos metanólicos das hortaliças foi determinada através do ensaio do DPPH. O teor de fenólicos totais foi obtido espectrofotometricamente de acordo com o método de Folin-Ciocalteu e calculado como equivalente de ácido gálico. A atividade antioxidante contra o radical livre DPPH foi: rúcula orgânica > almeirão orgânico > alface orgânica > rúcula convencional > almeirão convencional > alface convencional. O teor de fenólicos totais foi superior nos vegetais orgânicos. Os resultados deste estudo sugerem que as hortaliças orgânicas podem ser uma importante fonte de antioxidantes naturais e de compostos fenólicos e, portanto, seu consumo deve ser estimulado.Considering that consumers are becoming more conscious of their health and more concerned with environmental conditions, there has been an increasing demand for organic foods. The aim of this study was to compare the antioxidant activity and determine the total phenolic content of organic and conventional cultivations of lettuce, arugula, and chicory grown in the same vegetable garden. The antioxidant activity of the methanol extracts of these leaf vegetables wasdetermined using DPPH free radical scavenging assay. The total phenolic content in the extracts was determined spectrometrically according to the Folin-Ciocalteu method and calculated as equivalent of gallic acid. The antioxidant activity against the DPPH free radical was: organic arugula> organic chicory > organic lettuce > conventional arugula > conventional chicory > conventional lettuce. The total phenolic content

  11. Fenólicos totais e atividade antioxidante do extrato aquoso de broto de feijão-mungo (Vigna radiata L. Total phenolics and antioxidant activity of the aqueous extract of mung bean sprout (Vigna radiata L.

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Arroxelas Galvão de Lima

    2004-03-01

    Full Text Available OBJETIVO: Considerando a importância dos compostos fenólicos em alimentos e que o broto de feijão-mungo vem sendo incluído na culinária brasileira, este estudo teve como objetivo quantificar o teor de fenólicos totais deste vegetal e avaliar a ação antioxidante do seu extrato aquoso. MÉTODOS: Os compostos fenólicos foram extraídos por quatro sistemas de solventes e dois métodos de extração, os quais foram diferenciados no tempo (2 e 1h e número de extrações (2 e 3 extrações. Os fenólicos totais dos extratos foram quantificados por método espectrofotométrico. RESULTADOS: Os extratos obtidos com água à temperatura ambiente (28ºC, nos dois métodos de extração, foram os que apresentaram maior quantidade de fenólicos totais, sem contudo apresentar diferença significativa entre eles. O método II, que consistiu de três extrações em 1h, pode ser considerado o melhor por ter utilizado menor tempo de extração. O extrato aquoso em sistema modelo b-caroteno/ácido linoléico exibiu ação antioxidante (48,07% de inibição da oxidação, entretanto foi inferior ao padrão BHT. CONCLUSÃO: O broto de feijão-mungo possui considerável quantidade de fenólicos totais, compostos responsáveis por sua ação antioxidante, cujo consumo pode proporcionar efeitos benéficos à saúde.OBJECTIVE: Considering the importance of phenolic compounds in foods and the increasing consumption of mung bean sprouts in Brazil, this study had the objective of quantifying the total phenolic content in this vegetable and to assess the antioxidant activity of its aqueous extract. METHODS: The phenolic compounds were extracted by four solvent systems and two extraction methods, which were different in time (2 and 1h and in number of extractions (2 and 3 extractions. The total phenolic content of the extracts were quantified by the spectrophotometric method. RESULTS: The extracts obtained with water at room temperature (28ºC in both extraction

  12. Screening of High Ethyl Acetate Producing Yeasts for Fen-flavor ChineseSpirits Fermentation%清香型白酒优质产酯酵母菌筛选

    Institute of Scientific and Technical Information of China (English)

    王旭亮; 王异静; 王德良; 王丽华; 张五九

    2012-01-01

    为了提高清香型白酒的品质,以清香型发酵酒醅为筛选源,高产酯酵母Picha anomala CICC 1790,采用变色圈平板初筛,发酵力复筛,并结合乙酸乙酯生成能力测定及风味代谢物质分析,筛选出两株适合清香型白酒酿造,高产乙酸乙酯和乙酸菌株Ac-47和Ac-19,经鉴定均为Picha anomala。%To improve the quality of the Fen-flavor Chinese spirits, taking and high ethyl acetate producing Pieba anomala CICC 1790 as the control, Fen-flavor Chinese spirits fermentation Zaopei (the fermenting material during the fermentation) as the screening-source, color-changing circle as the first screening method, fermentation activity as the second screening method, together with ethyl acetate producing ability and some other flavor producing ability, selected two high ethyl acetate yielding and high acetic acid yielding strains, which numbered as Ac-47 and Ac-19, both identified as Picha anomala.

  13. Revealing Rembrandt

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    Andrew J Parker

    2014-04-01

    Full Text Available The power and significance of artwork in shaping human cognition is self-evident. The starting point for our empirical investigations is the view that the task of neuroscience is to integrate itself with other forms of knowledge, rather than to seek to supplant them. In our recent work, we examined a particular aspect of the appreciation of artwork using present-day functional magnetic resonance imaging (fMRI. Our results emphasised the continuity between viewing artwork and other human cognitive activities. We also showed that appreciation of a particular aspect of artwork, namely authenticity, depends upon the co-ordinated activity between the brain regions involved in multiple decision making and those responsible for processing visual information. The findings about brain function probably have no specific consequences for understanding how people respond to the art of Rembrandt in comparison with their response to other artworks. However, the use of images of Rembrandt’s portraits, his most intimate and personal works, clearly had a significant impact upon our viewers, even though they have been spatially confined to the interior of an MRI scanner at the time of viewing. Neuroscientific studies of humans viewing artwork have the capacity to reveal the diversity of human cognitive responses that may be induced by external advice or context as people view artwork in a variety of frameworks and settings.

  14. Rich fen development in SE Poland and its response to climate changes and human impacts in the late Holocene

    Science.gov (United States)

    Gałka, Mariusz; Apolinarska, Karina; Aunina, Liene; Feurdean, Angelica; Hutchinson, Simon; Kołaczek, Piotr

    2016-04-01

    Rich fens are one of the most important wetland ecosystems due to their high species-richness and unique species composition. They are occupied by endangered, vulnerable and protected plants, such as Cladium mariscus and Schoenus ferrugineus. For this reason knowledge of the history of rich fens is important for the development of effective management strategies to protect or restore these widely threatened habitats. Our palaeoecological study reconstructs the development of Bagno Serebryskie rich fen (ca. 376 ha), a site with the largest population of Cladium mariscus in CE Europe, and its response to climate changes and human impacts during the last 3500 years. For this we analyse two peat profiles at this site, at a high resolution (1 and 2 cm) using multi-aspect palaeoecological analyses (plant macrofossils, pollen, molluscs, geochemistry, charcoal and AMS 14C radiocarbon) to assess the impact of climate changes, human activity, and fires on local vegetation. Local plant succession in our two coring points followed parallel trajectories; after a lake stage, ca. 1800 cal yr BP (core I) and 3300 cal yr BP (core II), fen species e.g. Menyanthes trifoliata, Mentha aquatic, Carex lasiocarpa appeared, followed at ca. 500 cal. yr BP by Cladium mariscus, which is currently the dominant plant species in the Bagno Serebryskie peatland. In one peat profile (core II) we found abundant macrocharcoal particles at 1050, 700, 400 cal yr BP and the present, but fires had no significant impact on the development of the mire. In the other peat profile (core I) we noted four stages (at 2300, 1350, 400, 100 cal yr BP) with an increasing diversity of mollusc species typical of overgrown, but permanent water bodies. Their increased abundance and diversity can be linked to a rise in mire water table at these times. Our studies indicate that rich fens can provide reliable sites for palaeoecological reconstruction of the late Holocene providing valuable information that can be applied

  15. Seasonal variation in the phenol content of Eugenia uniflora L. leaves Variação sazonal nos teores de fenóis de folhas de Eugenia uniflora L

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    R.M Santos

    2011-01-01

    Full Text Available Hydrolysable tannins, total phenols and flavonoids in Eugenia uniflora leaves were monthly analysed for one year. The results were correlated with climate conditions (rainfall, humidity, cloudiness and mean temperature through chemometric methods. Principal component analysis revealed high levels of hydrolysable tannins in the rainy season, whereas flavonoids were mainly produced in the dry season. These facts suggest that climatic changes may be one of the factors affecting phenol levels in Eugenia uniflora.Taninos hidrolisáveis, fenóis totais e flavonóides presentes em folhas de Eugenia uniflora foram quantificados mensalmente durante um ano. Os resultados foram correlacionados com as condições climáticas (pluviosidade, umidade, nebulosidade e temperatura média através de métodos quimiométricos. Análise de componentes principais revelou a ocorrência de altos teores de taninos hidrolisáveis durante a estação de chuvas, enquanto os flavonóides foram produzidos principalmente na estação seca. Estes fatos sugerem que mudanças climáticas podem ser um dos fatores que afetam os níveis de fenóis em Eugenia uniflora.

  16. Determining the impact of Carex rostrata on methane cycling in a temperate fen

    Science.gov (United States)

    Noyce, G. L.; Varner, R. K.; Bubier, J. L.

    2010-12-01

    Northern peatlands hold ~30% of the world’s soil carbon and are the largest single natural source of atmospheric methane (CH4). Because this soil carbon is in close proximity to the atmosphere and much of it is permanently frozen, it is highly susceptible to a warming climate. Already, shifts in the dominant vegetation species have been observed in these regions as soils become wetter as a result of melting permafrost. Sedges grow well in saturated soils due to their aerenchymous tissues, which allow them to bring oxygen down to their roots. However, these tissues also act as a conduit of CH4 from peatland soils to the atmosphere. Positive correlations have been observed between sedge biomass and high CH4 emissions from a variety of wetland sites and thus an increase in sedge cover in a northern peatland could act as a positive feedback to climate change. We examined the effect that the sedge species Carex rostrata4 production, oxidation, and transport at Sallie’s Fen, Barrington, NH, through an ongoing vegetation removal experiment begun in June 2008. Originally, all plots were dominated by C. rostrata4 at 18 and 60 cm below the peat surface, sedge green area, water table depth, and peat and air temperature were measured once per week while sedges were actively growing (late March through September). On a daily basis, average CH4 flux from the control plots was usually higher than from the clipped plots and average summer CH4 flux for all years was larger from the control plots than from the clipped plots. Average CH4 flux in June, July, and August 2010 was 140 ± 67 mg CH4 m-2 day-1 for the control plots compared to 74 ± 20 mg CH4 m-2 day-1 for the experimental plots. We observed a strong positive correlation between C. rostrata4 flux. Incubations of the top 30 cm of peat conducted in 2010 show little difference in potential CH4 oxidation or potential CH4 production between treatments, but these results may be complicated by the particularly dry conditions

  17. A water-budget approach to restoring a sedge fen affected by diking and ditching

    Science.gov (United States)

    Wilcox, Douglas A.; Sweat, Michael J.; Carlson, Martha L.; Kowalski, Kurt P.

    2006-04-01

    A vast, ground-water-supported sedge fen in the Upper Peninsula of Michigan, USA was ditched in the early 1900 s in a failed attempt to promote agriculture. Dikes were later constructed to impound seasonal sheet surface flows for waterfowl management. The US Fish and Wildlife Service, which now manages the wetland as part of Seney National Wildlife Refuge, sought to redirect water flows from impounded C-3 Pool to reduce erosion in downstream Walsh Ditch, reduce ground-water losses into the ditch, and restore sheet flows of surface water to the peatland. A water budget was developed for C-3 Pool, which serves as the central receiving and distribution body for water in the affected wetland. Surface-water inflows and outflows were measured in associated ditches and natural creeks, ground-water flows were estimated using a network of wells and piezometers, and precipitation and evaporation/evapotranspiration components were estimated using local meteorological data. Water budgets for the 1999 springtime peak flow period and the 1999 water year were used to estimate required releases of water from C-3 Pool via outlets other than Walsh Ditch and to guide other restoration activities. Refuge managers subsequently used these results to guide restoration efforts, including construction of earthen dams in Walsh Ditch upslope from the pool to stop surface flow, installation of new water-control structures to redirect surface water to sheet flow and natural creek channels, planning seasonal releases from C-3 Pool to avoid erosion in natural channels, stopping flow in downslope Walsh Ditch to reduce erosion, and using constructed earthen dams and natural beaver dams to flood the ditch channel below C-3 Pool. Interactions between ground water and surface water are critical for maintaining ecosystem processes in many wetlands, and management actions directed at restoring either ground- or surface-water flow patterns often affect both of these components of the water budget. This

  18. Una mirada al fenómeno de la violencia escolar en Costa Rica

    Directory of Open Access Journals (Sweden)

    Leonel Arias Sandoval

    2009-06-01

    Full Text Available

    Recibido 30 de julio de 2008 • Aprobado 23 de marzo de 2009 • Corregido 20 de abril de 2009

     

    Resumen. En el actual contexto educativo, padres de familia, estudiantes, docentes, medios de comunicación y demás sectores de la sociedad costarricense, manifiestan su preocupación ante el problema de la violencia escolar, fenómeno social que ha venido en aumento en los últimos años. Sus manifestaciones se perciben por medio de conductas de maltrato, intimidación, agresión verbal o física entre jóvenes, y que se construye por medio de prácticas culturales. De ahí que, para comprender este problema, se debe reflexionar acerca de las posibles causas, teniendo en cuenta el contexto en el cual se desarrolla la convivencia social en cada centro educativo. Algunas de las manifestaciones de violencia tienen su origen en la familia, en la comunidad, en la imitación de patrones de conducta y en la influencia de los medios de información de masa. Además, estos comportamientos son potenciados por el modelo curricular vigente, lo que genera resistencia a las normas institucionales.

     

    Abstract. In the current context of education, parents, students, teachers, media and other sectors of Costa Rican society, express concern about the problem of school violence, a social phenomenon that has been increasing in recent years. Its manifestations are perceived by means of abuse behavior, intimidation, verbal or physical abuse among youth, which are constructed through cultural practices. Therefore, to understand this problem, reflection about possible causes is in order, taking into account the context in

  19. Hipertemia durante el fenómeno de el niño, 1997-98

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    Jaime Miranda M

    2003-10-01

    Full Text Available Objetivo: Describir el cuadro clínico y la evolución de los casos de síndrome febril presentados durante el fenómeno de "El Niño" de 1997-98, y presentar una revisión de la fisiopatología del cuadro de hipertermia. Material y métodos: Se realizó un estudio descriptivo longitudinal en la ciudad de Chimbote, Ancash. Se definió como caso de síndrome febril: niños menores de 5 años con fiebre refractaria al uso de antipiréticos sin foco aparente de infección. En el análisis posterior se consideraron: apariencia no tóxica, previamente sano, sin foco de infección al examen físico y con examen de laboratorio negativo. Resultados: Fueron estudiados 25 casos (68% varones, 80% con edades entre 5 y 18 meses con un tiempo de enfermedad promedio de 15,17(13,52 días ± desviación stándar (±DS. La mediana de la temperatura fue 38,8ºC con un promedio de 38,84ºC (rango 38 - 40ºC. 68% tuvo un tiempo de enfermedad mayor de 15 días; 52% había visitado al menos una vez un centro médico anterior; 68% recibió antibióticos y antipiréticos; y, 52 % ingresó al hospital por emergencia. Todos los casos presentaron alza térmica, asociado a piel seca (72%, diarrea (64%, tos (52%, baja de peso (52%, irritabilidad (44%, náuseas o vómitos (40%, rinorrea (24% y convulsiones (20%. El tiempo de hospitalización promedio fue 4,7 días y el estado febril promedio fue 2,5 días. Ninguno tuvo examen de laboratorio compatible con causa infecciosa. Conclusiones: En situaciones ambientales adversas debe considerarse al calor ambiental como un factor importante en el desarrollo de la hipertermia, con el propósito de brindar un manejo más apropiado a los afectados en el menor tiempo posible.

  20. Boko Haram: análisis del fenómeno terrorista en Nigeria

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    Francisco Javier Torregrosa López

    2016-04-01

    Full Text Available El terrorismo sufre cambios en la actualidad y evoluciona a la par que el resto del mundo. Boko Haram supone el ejemplo perfecto de un nuevo terrorismo emergente, alimentado por la globalización y la economía, pero fundamentado a su vez en pilares tan antiguos como el fanatismo religioso y los conflictos interculturales. En este artículo se trata de revisar las claves del nacimiento y desarrollo de este grupo terrorista: las características de su país de origen, los elementos que llevaron al surgimiento de este grupo terrorista, qué estrategias de asalto y financiación utiliza en la actualidad y cómo lleva a cabo Boko Haram: análisis del fenómeno terrorista en Nigeria Rafael López Pérez Doctor en Psicología. Presidente de la Fundación Universitaria Behavior & Law, Madrid, España. rlopez@behaviorandlaw.com Nahikari Sánchez Herrero Magíster en Seguridad. Especialidad en perfiles terroristas. Profesora de Crímina, Centro para el estudio y prevención de la delincuencia, Pamplona, España. nahikari.sanchez@crimina.es Ángel García Collantes Doctor en Derecho. Director de la Cátedra de Análisis de Conducta UDIMA - Fundación Universitaria Behavior & Law, Madrid, España. angel.garcia.c@udima.es Francisco Javier Torregrosa López Magíster en Criminología y Ciencias Forenses. Investigador en la Fundación Universitaria Behavior & Law, Alicante, España. javiertorregrosalopez@behaviorandlaw.com David Garriga Guitart Magíster en Mundo Árabe e Islámico. Analista de Terrorismo Yihadista, Fundación Universitaria Behavior & Law, Barcelona, España. dgarriga@behaviorandlaw.com su reclutamiento, así como su relación con otros grupos terroristas. Por último, con base en la teoría analizada, se realizará un análisis prospectivo sobre qué dirección es más probable que sigan sus acciones durante un futuro inmediato y a largo plazo. Las conclusiones alcanzadas por los autores indican que Boko Haram con probabilidad continuar

  1. Análisis comparativo de compuestos fenólicos totales y actividad antioxidante de cuatro marcas de tisanas de Hibiscus sabdariffa (Malvaceae comercializadas en Costa Rica

    Directory of Open Access Journals (Sweden)

    Melissa Agüero

    2014-01-01

    Full Text Available Las tisanas de rosa de Jamaica (Hibiscus sabdariffa son consumidas en Costa Rica por su conocido efecto cardioprotector asociado a la presencia de compuestos fenólicos, principalmente antocianinas. Este trabajo estableció diferencias en el perfil de compuestos fenólicos y su actividad anti-radical entre diferentes comercializadores de tisanas de Hibiscus sabdariffa en Costa Rica. Se identificaron cualitativamente taninos, flavonoides y antocianinas. Se cuantificó la cantidad total de compuestos fenólicos por el método de Folin-Ciocalteu y se cuantificó la actividad antioxidante con el método de DPPH. Todas las marcas comerciales demostraron presencia de compuestos fenólicos, incluyendo antocianinas; sin embargo, se encontraron diferencias significativas en el contenido de compuestos fenólicos y actividad anti-radical, entre los diferentes productores de tisanas. Por ello, se concluye que en el mercado costarricense, el perfil en compuestos fenólicos de las tisanas en estudio varía de acuerdo con el productor.

  2. The effect of an exceptionally wet summer on methane effluxes from a 15-year re-wetted fen in north-east Germany

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    V. Huth

    2013-10-01

    Full Text Available Re-wetting minerotrophic fens has become an important strategy to mitigate climate change in Germany. However, recent studies report raised methane (CH4 effluxes during the first years after flooding. A minerotrophic fen in north-east Germany that was re-wetted 15 years ago was exposed to exceptionally heavy rainfall and freshwater flooding in August 2011. We measured CH4 effluxes from wetland vegetation stands dominated by Phragmites australis (Cav. Trin. ex Steud., Typha latifolia L. and Carex acutiformis Ehrh., using the closed-chamber method, fortnightly from March 2011 to March 2012 with extra sampling during the flooding. The respective annual effluxes of CH4 (mean ± 1 standard error from the three vegetation types were 18.5 ± 1.3, 21.1 ± 1.2 and 47.5 ± 5.0 g m-2 a-1, with the August effluxes contributing 40 %, 50 % and 10 % of the annual effluxes. Despite the freshwater flooding in August, annual CH4 effluxes from the 15-year re-wetted fen are similar to those reported from pristine fens. These results are promising because they indicate that, although CH4 effluxes are elevated after re-wetting, they may return to values typical for pristine fens after 15 years. Hence, re-wetting can achieve the purpose of reducing greenhouse gas effluxes from drained minerotrophic fens.

  3. Violência como fenômeno intrínseco à cultura política brasileira

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    Antonio M. Soares

    2016-06-01

    Full Text Available Este artigo problematiza o conceito de violência e suas mutações através dos tempos. Como fenômeno cultural, a violência é construída na sociedade e se processa de forma a romper com os próprios códigos de ordens produzidos por ela. No caso do Brasil a violência se mostra intrínseca ao processo de formação da sociedade brasileira, estando presente nas lógicas autoritárias e na imposição cultural desde os tempos da colonização. A violência emerge como uma agressão ao indivíduo e ao coletivo, ela aniquila o sentido da política e desabilita o mundo comum. As interpretações presentes neste trabalho buscam aprofundar as análises sobre a violência enquanto fenômeno social e cultural, redimensionando os efeitos que ela produz para a condição humana e suas associações com as dimensões da civilidade, incivilidade e descivilidade. Neste contexto, destacaremos como o fenômeno da violência se afirmou como uma dimensão estrutural e cultural da formação da sociedade brasileira, como ele se revela na contemporaneidade, nos jogos de poder, nas relações de força e no movimento de fronteiras tênues entre o legal e o ilegal.

  4. Avaliação da Atividade Antioxidante dos Compostos Fenólicos Presentes na Amburana cearensis

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    Larisse de Oliveira dos Santos

    2016-02-01

    Full Text Available Amburana cearensis A. C. Smith (Fabaceae é conhecida popularmente por cumaru. Na medicina popular sua casca é largamente indicada para o tratamento de afecções respiratórias e como anti-inflamatório. Tendo conhecimento do seu potencial farmacológico este trabalho teve como objetivo avaliar a atividade antioxidante e de fenóis totais dos extratos etanólico bruto das folhas e casca (EEF e EEC e das frações metanólica e acetato de etila das folhas (FMeF e FAcF. A propriedade antioxidante dos extratos e frações foi determinada por método espectrofotométrico nas concentrações de 1,0; 0,1; 0,01 e 0,001 mg/mL . Para a determinação dos fenóis totais aplicou-se o método Folin-Ciocalteu expressos como equivalentes de ácido gálico (EAG por g amostra. Todas as amostras avaliadas apresentaram atividade antioxidante, contudo a amostra FMeF apresentou o maior valor para atividade (94% quando comparado ao padrão de  ácido ascórbico.  Com relação a fenóis totais o valor mais expressivo foi o do FAcF com 134,66 de mg EGA/g. DOI: http://dx.doi.org/10.17807/orbital.v1i1.706

  5. Lucio's phenomenon: another case reported in Brazil Fenômeno de Lúcio: mais um caso relatado no Brazil

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    Rodrigo Monteiro

    2012-04-01

    Full Text Available Lucio's phenomenon is defined as a variant of type 2 leprosy reaction. It is a rare event, occurring in the evolution of leprosy of Lucio and other forms of lepromatous leprosy. It has an exacerbated proliferation of Hansen bacilli in its pathophysiology, which invade blood vessel walls and injure endothelial cells, causing endothelial proliferation and decreasing the vascular lumen. This fact, associated with inflammatory reactions and changes in the coagulation system causes vascular thrombosis, ischemia, infarction and tissue necrosis, leading to the histopathological characteristic of the phenomenon. We report a case of lepromatous leprosy with irregular treatment that developed Lucio's phenomenon. Treatment with multidrug therapy, antibiotics, steroids and thalidomide achieved a favorable outcome.Define-se o fenômeno de Lúcio como uma variante da reação hansênica do tipo 2. Evento raro, que ocorre na evolução da hanseníase de Lúcio e de outras formas de hanseníase virchowiana. Tem na sua fisiopatologia uma proliferação exacerbada dos bacilos de Hansen, que invadem a parede dos vasos sanguíneos e agridem as células endoteliais, causando proliferação endotelial e diminuição do lúmen vascular, fato este, que associado a reações inflamatórias e a alterações no sistema da coagulação, causa trombose vascular, isquemia, infarto e necrose tecidual, gerando as alterações histopatológicas características do fenômeno. Relatamos um caso de hanseníase virchowiana, com tratamento irregular, que desenvolveu o fenômeno de Lúcio. Recebeu tratamento com poliquimioterapia, antibióticos, corticosteróide e talidomida, evoluindo com desfecho clínico favorável.

  6. La etimología popular como fenómeno peculiar de motivación del lenguaje

    OpenAIRE

    2010-01-01

    La etimología popular, a pesar de carecer de un tratamiento estrictamente riguroso y clarificador, constituye un importante mecanismo regenerador del léxico. Su incidencia en la competencia lingüística de los hablantes, así como su particular modo de actuación, nos ha llevado a iniciar una incursión en este ámbito. Si partimos de una nueva perspectiva realista acerca del lenguaje, haciendo hincapié en su naturaleza social, el estudio de este fenómeno se convierte en un elemento esencial a la ...

  7. Cuerpos e identidades en movimiento: El fenómeno promesante en la comuna de Calama, Chile

    OpenAIRE

    Mercado Guerra, Javier

    2014-01-01

    [spa] El presente trabajo indaga en el contexto cotidiano y en las prácticas rituales desarrolladas por cierto tipo de agrupaciones de danza -llamadas Bailes Religiosos- que residen en la comuna de Calama, Provincia de El Loa, Región de Antofagasta, Chile. Se propone una interpretación holística de este difundido fenómeno sociocultural, destacando la relevancia que tienen sus aspectos corporales y performativos. El trabajo plantea, por una parte, que la ritualidad y las danzas promesant...

  8. Fenómenos astrofísicos y la extinción de los dinosaurios

    OpenAIRE

    Claret dos Santos, Antonio

    2008-01-01

    Nuestra visión del Universo ha cambiado mucho en los últimos tiempos. En lugar del cielo tranquilo e inmutable que se creía antes, hoy sabemos que fenómenos astrofísicos de muy alta energía tienen lugar con cierta frecuencia y pueden actuar como uno de los motores de la evolución de las especies en la Tierra. Analizaremos las posibles implicaciones de los GRB (explosiones de rayos gamma), supernovae, impactos de cometas y/o meteoritos y de las variaciones orbitales en el caso particular de la...

  9. O diagnóstico em psicanálise: do fenômeno à estrutura

    OpenAIRE

    2000-01-01

    Este artigo desenvolve a questão do diagnóstico em psicanálise a partir de estudos feitos na pesquisa sobre o tema. Inicialmente, aborda-se a própria concepção de pesquisa em psicanálise e, a seguir, situa-se o conceito de estrutura, tal como formulado por Lacan, no cerne da discussão. Finalmente, apresenta-se a construção de um caso clínico para melhor localizar a relação entre fenômeno e estrutura.

  10. El fenómeno social de la educación como fundamento de las diferencias generacionales

    OpenAIRE

    Claudio Puerto, Arnalia

    1986-01-01

    Partiendo de la concepción del individuo como ser eminentemente social, se pasa a analizar por un lado a) la influencia que el medio social ejerce sobre el fenómeno educativo, estando dicha influencia mediatizada fundamentalmente por la personalidad del individuo, en cuya constitución participan elementos hereditarios o congénitos e influjos ambientales; y por otro, b) la influencia que la educación como tal ejerce en el medio, pudiendo ella propiciar un cambio social, en cuyo seno aparecería...

  11. El abstencionismo como fenómeno político en la sociedad contemporánea

    Directory of Open Access Journals (Sweden)

    Rogelio López Sánchez

    2013-01-01

    Full Text Available El objetivo de la presente contribución es analizar el abstencionismo como fenómeno político. En este sentido, se examinan las distintas facetas del mismo con la finalidad de acercarnos hacia un modelo de participación cívica racional en el contexto mexicano. Igualmente, se lleva a cabo una crítica en contra del monopolio partidista que deja a los ciudadanos un pequeño margen de cuestiones políticas en las cuales puedan tomar parte.

  12. Datos, fenómenos y representación: Sobre el estructuralismo empirista de van Fraassen

    Directory of Open Access Journals (Sweden)

    José Luis Rolleri

    2015-01-01

    Full Text Available Se analizan ciertos conceptos del estructuralismo empirista de Bas van Fraassen, en particular, el de representación, para intentar una crítica a su posición con respecto al vínculo entre los modelos de las teorías y, en última instancia, el mundo físico por medio de los modelos de datos, a los cuales van Fraassen les adjudica el papel de representantes de los fenómenos. Al final se delinea, a muy grandes rasgos, una alternativa conceptualista.

  13. Folhas de mandioca: caracterização de compostos fenólicos, atividades antioxidante e inseticida

    OpenAIRE

    Santos, Mírian Aparecida Isidro dos

    2014-01-01

    Os objetivos neste trabalho foram caracterizar os compostos fenólicos e avaliar as atividades antioxidante e inseticida da farinha de folhas de mandioca (FFM). Folhas maduras de mandioca (Manihot esculenta Crantz cv. Pão da China) foram coletadas aos 12 meses de idade da planta e transportadas ao laboratório. As folhas foram lavadas em água e em seguida colocadas em estufas com circulação de ar para secagem por 48 horas, à temperatura entre 30oC e 35oC. Após secagem, as folhas foram moídas pa...

  14. Examination of mercury and organic carbon dynamics from a constructed fen in the Athabasca oil sands region, Alberta, Canada using in situ and laboratory fluorescence measurements

    Science.gov (United States)

    Oswald, C.; Carey, S. K.

    2013-12-01

    In the Athabasca oil sands region, mined landscapes must be reclaimed to a functioning natural ecosystem as part of the mine closure process. To test wetland construction techniques on oil sands tailings, 55 ha of mined landscape on the Syncrude Canada Ltd. property is being reclaimed to a watershed containing a graminoid fen. The 18 ha constructed fen consists of an approximately 50 cm thick peat-mineral soil layer separated from underlying tailings sand by a thin layer of clay till. The water table in the fen is maintained by pumping water into the fen from a nearby lake and controlling outflow with under-drains. The objective of this study was to assess total mercury (THg) and methyl mercury (MeHg) concentration dynamics in water exported from the fen in relation to organic carbon quantity and composition. Water quality data from summer 2012 when the fen pumps were first turned on show that dissolved organic carbon (DOC) concentrations are on average twice as high in water flowing through the underlying tailings sand aquifer (median: 42.0 mg/L) compared to DOC concentrations in water flowing through the fen peat package (median: 20.3 mg/L). Given these DOC concentrations, filtered THg concentrations are very low (median values are 0.81 ng/L and 0.17 ng/L for water flowing through the fen peat and sand tailings, respectively) compared to concentrations reported for other boreal wetlands. Although a relationship was identified between filtered THg and DOC (r2=0.60), its slope (0.06 ng Hg/mg C) is an order-of-magnitude smaller than the typical range of slopes found at other wetland sites potentially suggesting a small pool of mercury in the peat and/or limited partitioning of mercury into solution. Filtered MeHg concentrations in all water samples are near the limit of detection and suggest that biogeochemical conditions conducive to methylation did not exist in the fen peat or tailings sand at the time of sampling. In addition to these baseline THg and Me

  15. Impact of Drying and Rewetting on Carbon Cycling in a Northern fen

    Science.gov (United States)

    Estop, C.; Blodau, C.

    2009-05-01

    Peatlands are quantitatively important carbon-storing terrestrial ecosystems where peat develops due to the rate of C input (organic matter as litter) surpassing that of C output (gas efflux and leaching) during biomass decomposition. High water contents are an important factor controlling such equilibrium in these soils since water does not become limiting for plant growth while keeping peat in a highly reduced state and thus lowering peat degradation rate. A predicted effect of current climate change is the potential alteration in the hydrological regime due to extreme rain events and extended dry periods. Thus, greater fluctuations in the water table levels may be expected to influence redox processes and carbon cycling in peatlands. We investigated respiration and transport processes in peat during manipulation of water table level at ecosystem scale in a small iron-rich fen located in a forested area of North Bavaria (Germany). The experimental design consists of three treatment (dry-rewetting) and three control plots where spatially high resolved peat profiles (2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20, 25, 30, 45 and 55 cm depth) were weekly followed up for 7 months. An approach combining gas (for CO2, CH4 and O2 analysis) and pore-water sampling allowed gaining insight into spatio-temporal gradients and linking those to water table fluctuations. Soil moisture, temperature and CO2 concentrations were also investigated by installing sensors in the upper peat layer to obtain data series during the investigated period. A seasonal drying event naturally occurred in the control plots during summer. The drying effect was thus reinforced in intensity and duration in the treatment plots. The main terminal electron accepting process was Fe(III)-reduction as suggested by high reduced iron and nearly undetected hydrogen sulphide concentrations. Water table manipulation affected peat redox processes with progressive suppression of Fe(III)-reduction during the drying period

  16. Metódica: Articulación sistema teórico, fenómeno y procesos en el objeto de estudio. Una perspectiva desde el fenómeno pobreza

    Directory of Open Access Journals (Sweden)

    Yajaira Jiménez Zabala

    2011-10-01

    Full Text Available En este artículo discutimos la visión metódica que toma como apoyo el pivote entre lo cualitativo, lo cuantitativo y el orden de complejidad, en un enfoque plurimetódico, a través del cual se construyó la visión de la pobreza como objeto de estudio. Tal selección, está justificada en tanto se entiende la pobreza como un fenómeno social complejo, por las diversas aristas que le identifican. La combinación de los enfoques metodológicos permitió la aprehensión de los diferentes aspectos del fenómeno y de sus interrelaciones en las representaciones de los actores sociales vinculados con el estudio. Lo cualitativo, se entiende como la simbiosis de prácticas interpretativas, que no privilegia una metodología sobre otra. Lo cuantitativo estuvo referido al uso de indicadores derivados de los soportes referenciales del problema; el orden de complejidad, atendió a la manifestación de lo simple en tanto nodo tensional complejo, que requiere una mirada diferente para su comprensión e interpretación.

  17. Fenóis totais, atividade antioxidante e constituintes químicos de extratos de Anacardium occidentale L., Anacardiaceae Total phenolics, antioxidant activity and chemical constituents from extracts of Anacardium occidentale L., Anacardiaceae

    Directory of Open Access Journals (Sweden)

    Mariana H. Chaves

    2010-03-01

    Full Text Available O presente artigo relata o isolamento e identificação do palmitato, oleato e linoleato de sitosterila, sitosterol, estigmasterol, 3-O-β-D-galactopiranosídeo do sitosterol, 3-O-β-Dgalactopiranosídeo do estigmasterol, 3-O-β-D-glicopiranosídeo do sitosterol e uma mistura de ácidos anacárdicos (monoeno e dieno do extrato etanólico de cascas do caule de Anacardium occidentale L., Anacardiaceae, bem como do sitosterol, estigmasterol, lupeol, β-amirina, catequina e epicatequina do extrato etanólico do tegumento da castanha de caju in natura. Os extratos EtOH da casca e do tegumento foram avaliados quanto ao conteúdo de fenóis totais e atividade antioxidante. O extrato etanólico das cascas do caule apresentou maior conteúdo de compostos fenólicos e percentual de atividade antioxidante.This paper describes the isolation and identification of a mixture of sitosteryl ester derivatives of fatty acids (palmitic, oleic and linoleic, sitosterol, stigmasterol, sitosterol-3-O-β-galactopyranoside, stigmasterol-3-O-β-galactopyranoside, sitosterol-3-O-β-glucopyranoside and a mixture of anacardic acids (monoene and diene from stem bark of Anacardium occidentale L., Anacardiaceae, as well as sitosterol, stigmasterol, lupeol, β-amyrin, catechin and epicatechin from in natura cashew nut testa. Ethanol extracts from stem bark and testa were analyzed for antioxidant activity and total phenol content. The ethanol extract from stem bark exhibited the maximum of antioxidant activity and phenol content.

  18. Ecophysiological mechanisms characterising fen and bog species: focus on variations in nitrogen uptake traits under different soil-water pH.

    Science.gov (United States)

    Nakamura, Takatoshi; Nakamura, Motoka

    2012-04-01

    Although the productivity and nitrogen (N)-use traits of mire plants differ dramatically between fens and bogs, soil N richness does not necessarily differ, whereas the soil-water pH is distinctly lower in bogs than in fens. The ecophysiological mechanisms underlying these relations are unclear. To assess the relative availability of N forms in relation to soil-water pH, we focused on the net N uptake rate per unit root weight (NNUR), glutamine synthetase activity and nitrate reductase activity, and performed reciprocal transplant experiments with the seedlings of fen (Carex lyngbyei) and bog (C. middendorffii) sedge species in intact habitat sites. The soil-water pH was clearly lower at the bog site, but the NH(4) (+), NO(3) (-) or dissolved organic-N concentrations did not differ between the fen and bog sites. The activity of both enzymes for inorganic-N assimilation did not differ among the sites and species. However, the fen species grown at bog sites showed a drastic decrease in the NNUR, suggesting a suppression of organic-N uptake. The bog species showed no NNUR difference between the sites. These results indicate that inorganic-N availability does not differ between the two habitats, but organic-N availability is lowered in a low-pH bog, particularly in the case of fen species. Therefore, the relative availability of N forms shows species-specific variations that depend on the differences in the soil-water pH of root zone, even at similar N richness, which would play a key role in plant distribution strategies in relation to the fen-bog gradient.

  19. El fenómeno del acoso laboral entre los trabajadores de la universidad O fenômeno mobbing entre os trabalhadores da universidade The phenomenon of mobbing among university employees

    Directory of Open Access Journals (Sweden)

    Fernando Justicia Justicia

    2007-12-01

    Full Text Available El objetivo del artículo es realizar una descripción del fenómemo mobbing -acoso laboral- en el contexto de la universidad. Los trabajos realizadossobre este problema no son muy prolíficos lo que puede explicar la gran dificultad para caracterizar el fenómeno en el ámbito universitario. En el presente trabajo presentamos los niveles de incidencia del acoso laboral entre la población universitaria, los tipos de acoso más frecuentes y los efectos producidos en las víctimas, con la finalidad de caracterizar y definir el problema. Al mismo tiempo, intentamos conocer la influencia de determinadas variables como la edad, género y tiempo de victimización. En este sentido, y de acuerdo con otros estudios realizados, encontramos diferencias estadísticas en función del género de las víctimas. Del mismo modo, los resultados apuntan que la frecuencia y duración del acoso laboral afectan negativamente a las víctimas provocando un empeoramiento de los efectos derivados del acoso.O objetivo deste artigo é realizar uma descrição do fenômeno mobbing -tormento e persecução no lugar do trabalho- no contexto da universidade. Há poucos trabalhos realizados sob este problema nos contextos de educação superior o que pode explicar a grande dificuldade para caracterizar o fenômeno no âmbito universitário. Neste artigo apresentamos os níveis de incidência entre a população universitária, os tipos de mobbing mais freqüentes e os efeitos produzidos nas vítimas com a finalidade de caracterizar e definir o problema. Ao mesmo tempo, tentamos conhecer a influência de determinadas variáveis tais como a idade, gênero ou o tempo de exposição ao fenômeno. Neste sentido, e em concordância com outros estudos realizados, encontramos diferenças estatísticas em função do gênero das vítimas. De igual forma, os dados apontam que a freqüência e duração da situação de persecução no trabalho afetam negativamente as vítimas provocando

  20. Degradação de xenobióticos por fungos filamentosos isolados de areia fenólica

    Directory of Open Access Journals (Sweden)

    J. H. Silva

    2000-09-01

    Full Text Available Microrganismos foram isolados de areia fenólica resultante de atividades metalúrgicas, utilizando meio mínimo para fungos e pentaclorofenol (PCF como única fonte de carbono. Após quatro repiques sucessivos em intervalos de 15 dias de incubação, as culturas foram plaqueadas em meio de Martin. Três gêneros de fungos foram isolados e identificados como Acremonium sp., Paecilomyces sp. e Penicillium sp. Estes foram testados para degradar os corantes índigo e RBBR (Azul Brilhante de Remazol - R e o organoclorado PCF. A descoloração do índigo foi de 99%, para Paecilomyces e Penicillium, e de 74%, para Acremonium, e a de RBBR foi de 16%, para Penicillium; 14%, para Acremonium, e 5%, para Paecilomyces. Usando azul de bromotimol como indicador de degradação de PCF, foram obtidos 24% de descoloração para Acremonium; 22%, para Penicillium, e 17%, para Paecilomyces Utilizando cromatografia gasosa, detectou-se degradação de PCF de 69%, para Penicillium; 65%, para Paecilomyces, e 40% para Acremonium, respectivamente. Os resultados mostraram que foi possível isolar microrganismos de uma areia de fundição, altamente contaminada com fenóis, e os fungos isolados foram capazes de degradar PCF e outros xenobióticos testados.

  1. Cyberbullying: percepções acerca do fenômeno e das estratégias de enfrentamento

    Directory of Open Access Journals (Sweden)

    Sidclay Bezerra Souza

    2014-01-01

    Full Text Available O cyberbullying, caracterizado como um dos tipos de violência em contexto educativo, apresenta-se como uma das principais causas do mal-estar vivido por seus protagonistas. O estudo inserido no Projeto Cyberbullying - o diagnóstico da situação em Portugal pretendeu compreender o fenômeno a partir das vivências de 118 estudantes do primeiro ano do Ensino Superior público português, que responderam a um questionário. Pudemos perceber a percepção dos alunos sobre o fenômeno e a importância que pares, professores e pais apresentam no enfrentamento e prevenção do cyberbullying. Tais resultados orientam-se no sentido do desenvolvimento sistêmico de comunidades que se fortalecem internamente para que cada um se sinta autorizado a intervir e a cuidar dos que nelas são vítimas de violência.

  2. Comparison of phenol content and antioxidant capacity of nuts Comparação entre o conteúdo de fenólicos e capacidade antioxidante de sementes

    Directory of Open Access Journals (Sweden)

    Lucile Tiemi Abe

    2010-05-01

    Full Text Available Frequent nut intake is associated with protective effects against cardiovascular diseases. In addition to the generally high contents of unsaturated fatty acids, polyphenol compounds seem to be also implicated in health promoting effects of nuts due to their antioxidant properties. In this way, eleven different kinds of nuts, including pinhao seeds (Araucaria angustifolia and Brazil nuts (Bertholletia excelsa, typical of Brazil, were analyzed for the content of phenol compounds, including the potent anti-mutagenic and anti-cancer ellagic acid, and antioxidant capacity of methanolic extracts. The antioxidant capacity varied a hundred times among the different nuts, from 1.2 to 120 mg of Trolox equivalents.100 g-1 (FW. Total ellagic acid was determined after acid hydrolysis of ellagitannins and ellagic acid glycosides, and it was detected in only 3 of the 11 samples. The content of free and total ellagic acid in nuts varied from 0.37 to 41 and from 149 (chestnuts to 823 (walnuts mg.100 g-1 (FW, respectively. Among nuts, samples with the highest contents of ellagic acid (walnuts and pecans also presented the highest total phenol contents and DPPH radical scavenging capacities. Pinhao seeds and Brazil nuts did not present significant amounts of phenols nor antioxidant capacity.O consumo frequente de nozes está associado a efeitos protetores contra doenças cardiovasculares. Além do alto teor de ácidos graxos insaturados, os compostos polifenólicos também parecem implicados nos efeitos promotores da saúde devido a suas propriedades antioxidantes. Desta forma, onze tipos de nozes/sementes, incluindo pinhão (Araucaria angustifolia e castanha-do-pará (Bertholletia excelsa, típicos do Brasil, foram analisados em relação ao seu conteúdo de fenólicos, incluindo ácido elágico, tido como potente antimutagênico e anticancerígeno, e capacidade antioxidante dos extratos metanólicos. A capacidade antioxidante variou cem vezes entre as

  3. Influência dos compostos fenólicos de especiarias sobre a lipoperoxidação e o perfil lipídico de tecidos de ratos Influence of spices phenolic compounds on lipoperoxidation and lipid profile of rats tissues

    Directory of Open Access Journals (Sweden)

    Ana Vládia Bandeira Moreira

    2004-12-01

    Full Text Available OBJETIVO: Este trabalho avaliou o efeito antioxidante dos compostos fenólicos de uma mistura de especiarias (mostarda, canela e erva-doce sobre o metabolismo dos ácidos graxos das séries ômega3 e ômega6. MÉTODOS: Ratos Wistar recém desmamados receberam dieta rica em gorduras essenciais e um chá de especiarias. Após 45 dias, os animais foram sacrificados e tiveram seus tecidos coletados para análise das substâncias reativas ao ácido tiobarbitúrico e perfil lipídico. RESULTADOS: O chá fornecido aos animais apresentou atividade antioxidante equivalente ao hidroxitolueno butilado. Foram identificados no chá, os ácidos fenólicos catecol, salicílico e caféico; as enzimas cicloxigenase e lipoxigenase foram inibidas pelos extratos ricos nestes ácidos fenólicos. O perfil de ácidos graxos apresenta diferença entre os grupos teste e controles. Todos os tecidos dos grupos teste apresentaram menores valores em lipoperoxidação, em comparação aos controles. CONCLUSÃO: Estes dados sugerem, portanto, um efeito antioxidante das substâncias fenólicas identificadas na mistura das especiarias, sobre os ácidos graxos das séries ômega3 e ômega6.OBJECTIVE: This work analyzed the influence of the phenolic compounds from a blend of spices (mustard, cinnamon and anise on the omega3 and omega6 fatty acids metabolism. METHODS: Weaned Wistar rats received a diet rich in essencial lipids and an infusion of blended spices for 45 days. After that period, they were sacrificed their tissues were collected and analized for the TBARS and lipid profile by CGMS. RESULTS: The tea of spices showed an antioxidant activity equivalent to that of the butylated hydroxytoluene. The following phenolic acids were identified in the infusion, using mass chromatography: cathecol, salicilic and cafeic; Lipooxygenase and ciclooxigenase enzymes were inhbited by the phenolic acid extracts. It was observed that the total amount of the fatty acids found in the test

  4. Microbial reduction of iron and porewater biogeochemistry in acidic peatlands

    Directory of Open Access Journals (Sweden)

    K. Küsel

    2008-05-01

    Full Text Available Temporal drying of upper soil layers of acidic methanogenic peatlands might divert the flow of reductants from CH4 formation to other electron-accepting processes due to a renewal of alternative electron acceptors. In this study, we evaluated the in situ relevance of Fe(III-reducing microbial activities in peatlands of a forested catchment that differed in their hydrology. Intermittent seeps reduced sequentially nitrate, Fe(III, and sulfate during periods of water saturation. Due to the acidic soil conditions, released Fe(II was transported with the groundwater flow and accumulated as Fe(III in upper soil layers of a lowland fen apparently due to oxidation. Microbial Fe(III reduction in the upper soil layer accounted for 26.7 and 71.6% of the anaerobic organic carbon mineralization in the intermittent seep and the lowland fen, respectively. In an upland fen not receiving exogenous Fe, Fe(III reduction contributed only to 6.7%. Fe(II and acetate accumulated in deeper porewater of the lowland fen with maximum concentrations of 7 and 3 mM, respectively. Both supplemental glucose and acetate stimulated the reduction of Fe(III indicating that fermentative, incomplete, and complete oxidizers were involved in Fe(II formation in the acidic fen. Amplification of DNA yielded PCR products specific for Acidiphilium-, Geobacter-, and Geothrix-, but not for Shewanella- or Anaeroromyxobacter-related sequences. Porewater biogeochemistry observed during a 3-year-period suggests that increased drought periods and subsequent intensive rainfalls due to global climate change will further favor Fe(III and sulfate as alternative electron acceptors due to the storage of their reduced compounds in the soil.

  5. Microbial reduction of iron and porewater biogeochemistry in acidic peatlands

    Directory of Open Access Journals (Sweden)

    K. Küsel

    2008-11-01

    Full Text Available Temporal drying of upper soil layers of acidic methanogenic peatlands might divert the flow of reductants from CH4 formation to other electron-accepting processes due to a renewal of alternative electron acceptors. In this study, we evaluated the in situ relevance of Fe(III-reducing microbial activities in peatlands of a forested catchment that differed in their hydrology. Intermittent seeps reduced sequentially nitrate, Fe(III, and sulfate during periods of water saturation. Due to the acidic soil conditions, released Fe(II was transported with the groundwater flow and accumulated as Fe(III in upper soil layers of a lowland fen apparently due to oxidation. Microbial Fe(III reduction in the upper soil layer accounted for 26.7 and 71.6% of the anaerobic organic carbon mineralization in the intermittent seep and the lowland fen, respectively. In an upland fen not receiving exogenous Fe, Fe(III reduction contributed only to 6.7%. Fe(II and acetate accumulated in deeper porewater of the lowland fen with maximum concentrations of 7 and 3 mM, respectively. Both supplemental glucose and acetate stimulated the reduction of Fe(III indicating that fermentative, incomplete, and complete oxidizers were involved in Fe(II formation in the acidic fen. Amplification of DNA yielded PCR products specific for Acidiphilium-, Geobacter-, and Geothrix-, but not for Shewanella- or Anaeroromyxobacter-related sequences. Porewater biogeochemistry observed during a 3-year-period suggests that increased drought periods and subsequent intensive rainfalls due to global climate change will further favor Fe(III and sulfate as alternative electron acceptors due to the storage and enhanced re-oxidation of their reduced compounds in the soil.

  6. Selective Inhibition of Human Group IIA-secreted Phospholipase A2 (hGIIA) Signaling Reveals Arachidonic Acid Metabolism Is Associated with Colocalization of hGIIA to Vimentin in Rheumatoid Synoviocytes*

    Science.gov (United States)

    Lee, Lawrence K.; Bryant, Katherine J.; Bouveret, Romaric; Lei, Pei-Wen; Duff, Anthony P.; Harrop, Stephen J.; Huang, Edwin P.; Harvey, Richard P.; Gelb, Michael H.; Gray, Peter P.; Curmi, Paul M.; Cunningham, Anne M.; Church, W. Bret; Scott, Kieran F.

    2013-01-01

    Human group IIA secreted phospholipase A2 (hGIIA) promotes tumor growth and inflammation and can act independently of its well described catalytic lipase activity via an alternative poorly understood signaling pathway. With six chemically diverse inhibitors we show that it is possible to selectively inhibit hGIIA signaling over catalysis, and x-ray crystal structures illustrate that signaling involves a pharmacologically distinct surface to the catalytic site. We demonstrate in rheumatoid fibroblast-like synoviocytes that non-catalytic signaling is associated with rapid internalization of the enzyme and colocalization with vimentin. Trafficking of exogenous hGIIA was monitored with immunofluorescence studies, which revealed that vimentin localization is disrupted by inhibitors of signaling that belong to a rare class of small molecule inhibitors that modulate protein-protein interactions. This study provides structural and pharmacological evidence for an association between vimentin, hGIIA, and arachidonic acid metabolism in synovial inflammation, avenues for selective interrogation of hGIIA signaling, and new strategies for therapeutic hGIIA inhibitor design. PMID:23482564

  7. Greenhouse gas emissions from a drained fen peatland cultivated with reed canary grass for biogas production

    Energy Technology Data Exchange (ETDEWEB)

    Kandel, T.P.

    2013-10-01

    Cultivated peatlands are significant sources of CO{sub 2} as the drainage and subsequent agricultural practices such as tillage and fertilization enhances the decomposition of soil organic carbon. However, use of the peatlands for perennial energy crop production could help to reduce the CO{sub 2} emissions as annual ploughing is avoided in perennial cropping systems and fertilizer requirements is also lower compared to annual arable crops. However, crop managements such as fertilization and harvesting of those energy crops are also important in respect to total GHG balance. Moreover, economical viability of energy crop production in peatland need to be considered which requires studies on best management practices to produce high biomass and energy per hectare of land with as little input of resources as possible. In the first study, annual net ecosystem balance of CO{sub 2} from a riparian fen peatland used for annual arable crop and perennial energy crop cultivation was compared. Fluxes of CO{sub 2} were measured with closed chambered methods which were later partitioned into light depended gross photosynthesis (GP) and light independent ecosystem respiration (R{sub E}). The annual flux of CO{sub 2} was estimated by modelling GP and R{sub E} separately and extrapolating the obtained parameters in relation to environmental and biomass measurements. Model performances of commonly used GP and R{sub E} models were enhanced by introducing ratio vegetation index (RVI) as proxy for active leaf area index. Both GP and R{sub E} showed strong seasonal pattern as expected. An expected higher annual GP was observed in the RCG cultivation system which was favored by a longer growth period, but R{sub E} was also higher which was mainly contributed by higher plant respiration. Annual net ecosystem exchange (NEE) of CO{sub 2} was close to zero for both cropping systems and thus no apparent advantage of the energy cropping system was observed during crop cultivation. Another

  8. Highly exposed Fe-N4 active sites in porous poly-iron-phthalocyanine based oxygen reduction electrocatalyst with ultrahigh performance for air cathode.

    Science.gov (United States)

    Anandhababu, Ganesan; Abbas, Syed Comail; Lv, Jiangquan; Ding, Kui; Liu, Qin; Babu, Dickson D; Huang, Yiyin; Xie, Jiafang; Wu, Maoxiang; Wang, Yaobing

    2017-02-14

    Progress in the development of efficient electrocatalysts for oxygen reduction reactions is imperative for various energy systems such as metal-air batteries and fuel cells. In this paper, an innovative porous two-dimensional (2D) poly-iron-phthalocyanine (PFe-Pc) based oxygen reduction electrocatalyst created with a simple solid-state chemical reaction without pyrolysis is reported. In this strategy, silicon dioxide nanoparticles play a pivotal role in preserving the Fe-N4 structure during the polymerization process and thereby assist in the development of a porous structure. The new polymerized phthalocyanine electrocatalyst with tuned porous structure, improved specific surface area and more exposed catalytic active sites via the 2D structure shows an excellent performance towards an oxygen reduction reaction in alkaline media. The onset potential (E = 1.033 V) and limiting current density (I = 5.58 mA cm(-2)) are much better than those obtained with the commercial 20% platinum/carbon electrocatalyst (1.046 V and 4.89 mA cm(-2)) and also show better stability and tolerance to methanol crossover. For practical applications, a zinc-air (Zn-air) battery and methanol fuel cell equipped with the PFe-Pc electrocatalyst as an air cathode reveal a high open circuit voltage and maximum power output (1.0 V and 23.6 mW cm(-2) for a methanol fuel cell, and 1.6 V and 192 mW cm(-2) for the liquid Zn-air battery). In addition, using the PFe-Pc electrocatalyst as an air cathode in a flexible cable-type Zn-air battery exhibits excellent performance with an open-circuit voltage of 1.409 V. This novel porous 2D PFe-Pc has been designed logically using a new, simple strategy with ultrahigh electrochemical performances in Zn-air batteries and methanol fuel cell applications.

  9. The synthesis of Fe-N co-doping nano TiO2/SO42-%Fe-N共掺杂纳米TiO2/SO42-的合成

    Institute of Scientific and Technical Information of China (English)

    张忠坤; 郭国伟; 张昊; 王玉童; 韩丽; 王剑峰

    2015-01-01

    Fe-N co-doping nano-particles TiO2/SO42- is synthesized by sol-gel method using titanium tetraisopropoxide as the precursor, n-propanol as solvent, concentrated sulfuric acid as catalyst and inhibitor, acetylacetone as stabilizer, Fe2(SO4)3 as iron source and urea as nitrogen source. The prepared products are characterized by XRD, SEM, UV-vis, and BET surface area. The results indicated that the Fe-N co-doping TiO2/SO42- nano-particles have been synthesized as anatase. The absorption edge of the material showed red-shift gradually with doping weight of Fe-N increasing, in which the most appropriate weight of both of Fe and N is 3.0 wt%. The absorption edge of the material reaches 495 nm.The absorption intensity of the material in the visible region increases with the increase of doping concentration.%以工业级异丙醇钛为钛源,正丙醇为溶剂,浓硫酸为催化剂和抑制剂,乙酰丙酮为稳定剂,硫酸铁为铁源,尿素为氮源,采用溶胶-凝胶法制备了Fe-N共掺杂的纳米TiO2/SO42-。利用XRD、UV-vis、N2吸附脱附、SEM对所制备的材料进行了表征。结果表明:合成的Fe-N共掺杂的纳米TiO2/SO42-为锐钛矿型,随着掺杂量的增加,吸收边逐渐红移,在Fe和N掺杂量均为3.0 wt%时红移效果最佳,且吸收边红移至495 nm附近,在可见光区的吸收强度随着掺杂量的增加而增大。

  10. Caracterização do fenótipo gengival com análise por fotografia digital - estudo de uma amostra populacional de Viseu

    OpenAIRE

    Peixoto, Ana Isabel da Silva

    2012-01-01

    No estabelecimento de um diagnóstico de uma situação clínica na cavidade oral devem-se considerar várias características, entre as quais o fenótipo gengival. O fenótipo gengival é o conjunto das características morfogénicas da gengiva de cada indivíduo, incluindo a aparência do tecido mole, características genéticas e a forma como reage depois da manipulação. Existem dois fenótipos gengivais extremos que devemos ter especial consideração: um mais fino e frágil associado a uma margem festonada...

  11. Compostos fenólicos e capacidade antioxidante de cultivares de uvas Vitis labrusca L. e Vitis vinifera L. Phenolic compounds and antioxidant activity of Vitis labrusca and Vitis vinifera cultivars

    Directory of Open Access Journals (Sweden)

    Lucile Tiemi Abe

    2007-06-01

    Full Text Available O conteúdo de compostos fenólicos, incluindo resveratrol, antocianinas e outros flavonóides, e a capacidade antioxidante de cinco cultivares de uvas produzidas em Minas Gerais foram determinados. O conteúdo de fenólicos totais, determinado através do método de Folin-Ciocalteau variou significativamente, entre 65 ± 1 e 390 ± 30 mg equivalentes de ácido gálico.100 g -1 de amostra base úmida (b.u.. O conteúdo de antocianinas totais quantificado por CLAE variou entre 6,7 ± 0,2 e 154 ± 4 mg equivalentes de cianidina.100 g -1 (b.u.. Outros flavonóides encontrados foram catequina, epicatequina, quercetina, caempferol além dos ácidos hidroxicinâmicos. O resveratrol foi encontrado em três cultivares, variando entre 0,022 ± 0,001 e 0,60 ± 0,03 mg.100 g -1 (b.u.. A capacidade antioxidante foi analisada usando o método de seqüestro de radicais livres do DPPH (2,2-difenil-1-picrilhidrazila, que variou entre 2,7 ± 0,1 e 19 ± 2 µmoles equivalentes de Trolox.g -1 de amostra (b.u., mostrando boa correlação com o conteúdo de fenólicos totais. As uvas tintas de coloração mais escura apresentaram maior conteúdo de antocianinas, e conseqüentemente maior teor de fenólicos totais e capacidade antioxidante.Phenolic compounds including resveratrol, anthocyanins and other flavonoids and antioxidant capacity were evaluated for five grape cultivars cultivated in Minas Gerais (Brazil. The content of total phenolic determined by the Folin Ciocalteau method varied significantly, from 65 ± 1 to 390 ± 30 mg gallic acid equivalents.100 g -1 of FW (Fresh Weight. The content of total anthocyanins quantified by HPLC varied from 6.7 ± 0.2 to 154 ± 4 mg of cyanidin equivalents.100 g -1 FW. Resveratrol was found in three cultivars, in contents from 0.022 ± 0.001 to 0.60 ± 0.03 mg.100 g¹ of FW. In addition to hydroxicynnamic acids, other flavonoids such as catechin, epicatechin, quercetin and kaempferol were also present. The antioxidant

  12. The influence of vegetation structure on spider species richness, diversity and community organization in the Apšuciems calcareous fen, Latvia

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    Štokmane, M.

    2016-07-01

    Full Text Available Calcareous fens are considered to be among the most threatened ecosystems of Europe. They are also one of the most diverse habitats as they support an incredibly rich and diverse range of plant and animal species. However, in spite of their diversity, calcareous fens are still poorly investigated, especially when referring to fen invertebrates, such as spiders. Because spiders are good bioindicators, knowledge of their ecology in rare and threatened habitats is of interest. The aim of this study was to document the composition and diversity of spider species, families and foraging guilds in the ground– and grass–layers of the Apšuciems calcareous fen, and to evaluate the influence of vegetation structure on spider community organization. In summer 2012, we collected ground–dwelling spiders using pitfall traps and grass–dwelling spiders using sweep–netting. A total of 2,937 spider individuals belonging to 19 families and 80 species was collected in the Apšuciems fen. Our results indicate that spider species and families tend to be stratified across the vertical structure of the habitat; the spider composition in the ground stratum differed from that in the grass stratum. On the contrary, however, the spider foraging guild structure between the ground–layer and the grass–layer was similar. Each of the two studied strata presented similar guilds in similar proportions. Our results also showed that spider composition differed considerably between fen parts and that much of this variability could be explained by the architectural properties of the habitat. More diverse vegetation generally supported a higher number of spider species.

  13. Selective inhibition of jasmonic acid accumulation by a small α, β-unsaturated carbonyl and phenidone reveals different modes of octadecanoid signalling activation in response to insect elicitors and green leaf volatiles in Zea mays

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    Engelberth Jurgen

    2011-10-01

    Full Text Available Abstract Background Plants often release a complex blend of volatile organic compounds (VOC in response to insect herbivore damage. Among those blends of VOC green leaf volatiles (GLV have been demonstrated to function as defence signals between plants, thereby providing protection against impending herbivory. A problem in understanding the mode of action of these 6-carbon aldehydes, alcohols, and esters is caused by their structural diversity. Besides different degrees of oxidation, E-2- as well as Z-3-configured isomers are often released. This study was therefore initiated to determine the structural requirement necessary to exhibit biological activity measured as jasmonic acid (JA accumulation in Zea mays seedlings. Findings The structure/function analysis of green leaf volatiles and related compounds revealed that an olefinic bond in position 2 or 3 and a size of 6-8 carbons is required for biological activity in maize. Also, it was found that the presence of an α, β-unsaturated carbonyl is not a prerequisite for activity. However, by treating plants first with volatile acrolein it was discovered that this smallest α, β-unsaturated carbonyl inhibits JA accumulation in response to insect elicitor treatment, but not after GLV exposure. This selective inhibitory effect was also found for phenidone, an inhibitor of lipoxygenases. These findings led to the discovery of a pool of protein-associated 12-oxo-phytodienoic acid, a biosynthetic precursor of JA, which appeared to be rapidly converted into JA upon exposure to GLV. Conclusions The structure/function analysis of GLV demonstrates a high degree of correlation between the compounds released by wounded plants in nature and their biological activity. The selective inhibitory effects of acrolein and phenidone on insect elicitor- and GLV-induced JA accumulation in maize led to the discovery of a pool of protein-associated precursor, which is rapidly activated and transformed to JA after

  14. Fenômeno de Lúcio (eritema necrosante na gestação The Lucio's phenomenon (necrotizing erythema in pregnancy

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    Karin Adriane Helmer

    2004-04-01

    Full Text Available O fenômeno de Lúcio, variante do estado reacional hansênico tipo 2, provavelmente mediado por imunocomplexos, caracteriza-se por reação cutânea necrosante grave que ocorre principalmente em doentes portadores de hanseníase virchowiana não nodular. Os autores relatam o caso de uma paciente de 27 anos, do sexo feminino, gestante de 32 semanas, com quadro de lesões eritêmato-purpúricas nos membros, bem delimitadas, confluentes, encimadas por bolhas, algumas necróticas e ulceradas, com uma semana de evolução, acompanhadas de febre e intensa dor local. A baciloscopia da linfa evidenciou bacilos álcool-acidorresistentes formando globias, e a histopatologia da pele confirmou hanseníase virchowiana, compatível com fenômeno de Lúcio. Foi iniciada prednisona e poliquimioterapia multibacilar com rifampicina, clofazimina e sulfona, com boa evolução. A gravidez tem sido associada à elevada incidência de aparecimento dos primeiros sinais ou ao agravamento da hanseníase por alterações hormonais que levam ao desequilíbrio imunológico, sendo considerado crítico o período compreendido entre o último trimestre de gestação e os primeiros três meses da lactação, quando a imunossupressão atinge seu ápice. Apesar da recomendação de se restringir a ingestão de drogas na gestação, o tratamento da hanseníase deve ser realizado, visto que seus benefícios superam os riscos.The Lucio's phenomenon, a type 2 reactional condition in leprosy probably mediated by immune complexes, is a severe necrotizing skin reaction that occurs mainly in patients with non-nodular lepromatous leprosy. This report presents a 27-year-old woman, in her 32nd week of pregnancy, with a one-week history of painful skin lesions in extremities, reddish-purple, sharply delineated, confluent, with bullae and occasional necrosis and ulceration. The patient also referred fever. Baciloscopy showed acid-fast bacilli and globi, and the histopathologic findings of a

  15. La adherencia en el concreto reforzado: breve revisión histórica de la investigación del fenómeno

    OpenAIRE

    Norberto Domínguez Ramírez

    2013-01-01

    La interacción acero-concreto (o adherencia) es un fenómeno de vital importancia para las es - tructuras de concreto reforzado, al ser clave en la transferencia de esfuerzos entre las varillas de acero y el concreto circundante. La compren - sión de dicho fenómeno ha sido objeto de ar - duas investigaciones llevadas a cabo desde los albores de la construcción y un sinnúmero de és - tas se han realizado para incluir su influencia en el análisis, diseño y reglamentación de estructuras de concre...

  16. El sinsentido como problema hermenéutico en el fenómeno de las nuevas tecnologías

    OpenAIRE

    Cortés Boussac, Andrea

    2009-01-01

    El propósito de este artículo es mostrar cómo el olvido del Ser (Seinsvergessenheit) del primer Heidegger se puede aplicar a su segunda fase en la que se cuestiona por el fenómeno de la técnica. Se mostrará el sinsentido en el mundo poscapitalista-globalizado como un olvido del Ser del hombre; partiendo de la propuesta hermenéutica heideggeriana. Al mismo tiempo se explicará el fenómeno de las nuevas tecnologías; partiendo de la pregunta por la técnica de Heidegger. En otras palabras; se inte...

  17. El Frente Estudiantil Nacional (FEN): juventud y estudiantado en el proceso contestatario de los años sesenta en Argentina

    OpenAIRE

    2009-01-01

    Este artículo forma parte de un proyecto más amplio que aborda el proceso de acercamiento al Peronismo por parte de un sector del movimiento estudiantil en Argentina durante los años sesentas, tomando el caso particular del Frente Estudiantil Nacional (FEN). El FEN fue una organización universitaria “de pasaje al peronismo”, que buscaba inserción “legítima” en el mismo, vinculándose a sectores del peronismo histórico y al trabajo barrial.Proponemos privilegiar el análisis de documentos, aunqu...

  18. Consideraciones antropol??gicas frente al fen??meno de la religiosidad popular en comunidades campesinas de origen ind??gena en M??xico

    OpenAIRE

    2008-01-01

    La religiosidad popular dentro de las comunidades campesinas de origen ind??gena en M??xico, es un fen??meno que supera con mucho el ??mbito meramente piadoso-devocional. M??s bien se constituye como un fen??meno sumamente complejo en el cual convergen elementos religiosos, econ??micos, pol??ticos, sociales e identitarios, donde se pone en juego la relaci??n dial??ctica entre grupos culturales minoritarios frente a las hegemon??as pol??tica y religiosa del Estado mexicano. La organizaci??n so...

  19. El tratamiento de fenómenos físicos para aprender matemáticas

    OpenAIRE

    Cortés, Gildardo; Ramírez, Pericles

    2005-01-01

    La historia de la ciencia muestra la íntima relación entre la física y la matemática y cómo en nuestros días esta relación, en el ambiente escolar, se ha ido perdiendo. Nuestro planteamiento intenta recuperar el papel de la experimentación en el aula. Proponemos diseños de aprendizaje basados en prácticas de modelación de fenómenos físicos, para que alumnos construyan conocimientos con significado. En el documento damos evidencia de cómo este planteamiento puede ser posible. La investigación ...

  20. Representação e significação nos fenômenos comunicacionais

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    Luís Carlos Lopes

    2001-01-01

    Full Text Available Este trabalho consiste em uma investigação teórica sobre a importância das teorias da representação, significação e interpretação para o estudo dos fenômenos comunicacionais. O autor explica o que entende por comunicação e seus estudos. Discute algumas das bases epistemológicas dos estudos comunicacionais, em termos de universalidade, particularidade e naturalização. Baseia seu trabalho nas obras de Bourdieu, Debord, Canclini, Martín-Barbero, Sloterdijk, Habermas e, fundamentalmente, na de Putnam. 

  1. Magnetization switching behavior with competing anisotropies in epitaxial Co3FeN /MnN exchange-coupled bilayers

    Science.gov (United States)

    Hajiri, T.; Yoshida, T.; Jaiswal, S.; Filianina, M.; Borie, B.; Ando, H.; Asano, H.; Zabel, H.; Kläui, M.

    2016-11-01

    We report unusual magnetization switching processes and angular-dependent exchange bias effects in fully epitaxial Co3FeN /MnN bilayers, where magnetocrystalline anisotropy and exchange coupling compete, probed by longitudinal and transverse magneto-optic Kerr effect (MOKE) magnetometry. The MOKE loops show multistep jumps corresponding to the nucleation and propagation of 90∘ domain walls in as-grown bilayers. By inducing exchange coupling, we confirm changes of the magnetization switching process due to the unidirectional anisotropy field of the exchange coupling. Taking into account the experimentally obtained values of the fourfold magnetocrystalline anisotropy, the unidirectional anisotropy field, the exchange-coupling constant, and the uniaxial anisotropy including its direction, the calculated angular-dependent exchange bias reproduces the experimental results. These results demonstrate the essential role of the competition between magnetocrystalline anisotropy and exchange coupling for understanding and tailoring exchange-coupling phenomena usable for engineering switching in fully epitaxial bilayers made of tailored materials.

  2. Effects of N and P fertilisation on greenhouse gas (GHG) production in floodplain fen peat: A microcosm fertilisation experiment.

    Science.gov (United States)

    Stanley, Kieran; Heppell, Catherine; Belyea, Lisa; Baird, Andrew

    2016-04-01

    Biogeochemical and hydrological cycles are being significantly perturbed by anthropic activities altering atmospheric mole fractions of greenhouse gases (GHG) and increasing global temperatures. With the intensification of the hydrological cycle, lowland areas, such as floodplain fens, may be inundated more frequently. Rivers in agricultural catchments have the potential to pollute floodplain fens with significant amounts of nitrogen (N) and phosphorus (P); however, the effects of short-term (51 mg L-1 NO3-N) and P (1.4 mg L-1 PO43--P) additions may alter GHG (CO2, CH4, and N2O) production in floodplain fens of contrasting nutrient status under anaerobic conditions. A five-level (control, glucose (G), N+G, P+G, and N+P+G), fully-factorial microcosm experiment was designed and undertaken in Spring 2013 with peat from two floodplain fens under conservation management with similar vegetation (from Norfolk, United Kingdom). One site receives a higher nutrient load than the other and has a historical legacy of higher N and P contents within the peat. Results from the experiment showed no significant difference in CO2 production between the control and fertilised treatments from 0 to 96 hours, but a significant difference between treatments (ANCOVA, between factors: treatment and site; covariate: time; F4,419 = 11.844, p < 0.001) and site (F1,149 = 5.721, p = 0.017) from 96 hours to in the end of the experiment due to fermentation. N2O production only occurred in samples fertilised with N (N+G and N+P+G) due to denitrification. Rates of N2O production were significantly greater in samples from the lower-nutrient site in comparison to the nutrient-rich site (t12= 6.539, p < 0.001 and t12= 7.273, p < 0.001 for N+G and N+P+G fertilised samples, respectively). Fertilisation with N and P had different effects on CH4 production. Samples fertilised with P+G had the highest CH4 production (ANCOVA, between factors: treatment and site; covariate: time; F4,120= 15.026, p < 0

  3. Greenhouse gas emissions of drained fen peatlands in Belarus are controlled by water table, land use, and annual weather conditions

    Science.gov (United States)

    Burlo, Andrei; Minke, Merten; Chuvashova, Hanna; Augustin, Jürgen; Hoffmann, Mathias; Narkevitch, Ivan

    2014-05-01

    Drainage of peatlands causes strong emission of the greenhouse gases (GHG) CO2 and N2O, sometimes combined with a weak CH4 uptake. In Belarus drained peatlands occupy about 1505000 ha or more than 7.2 % of the country area. Joosten (2009) estimates CO2 emission from degraded peatlands in Belarus as 41.3 Mt yr-1 what equals to 47 % of total anthropogenic greenhouse gases (GHGs) emission of country in 2011. However, it could not be checked if these numbers are correct since there are no GHG measurements on these sites up to now. Therefore we studied the GHG emissions with the closed chamber approach in four peatlands situated in central and southern Belarus over a period from August 2010 to August 2012. The measurements comprised eight site types representing different water level conditions, and ranging from grassland and arable land over abandoned fields and peat cuts to near-natural sedge fens. Fluxes of CH4 and N2O were determined using the close-chamber approach every second week in snow free periods and every fourth week during winter time. The annual emissions were calculated based on linear interpolation. Carbon dioxide exchange was measured with transparent and opaque chambers every 3-4 weeks and the annual net ecosystem exchange (NEE) was modeled according to Drösler (2005). Most of the drained sites were sources of CO2 in both years. NEE increased with lower mean annual water table level. The highest NEE value (1263.5 g CO2-C m-1yr-1) was observed at the driest site of the study; an abandoned fen formerly used for agriculture. In contrast, a former peat extraction site with moist peat and small Pinus sylvestris tress were sinks of CO2 with uptake to 389.6 g CO2-C m-1yr-1. The highest N2O emissions were recorded at a drained agricultural fen with mean annual rates of up to 2347 mg N2O-N m-2 yr-1. Significant fluxes of CH4 (15 g CH4C m-2 h-1) were observed only at the near-natural site in the first year of investigation when precipitation and the mean water

  4. Uso de resíduo industrial a base de resina fenólica como carga para o polipropileno

    OpenAIRE

    André P. Cavalcante; Leonardo B. Canto

    2012-01-01

    O objetivo deste estudo foi analisar a viabilidade técnica do uso de resíduo industrial composto de resina fenólica, lignocelulose, carbonato de cálcio, talco, mica e negro de fumo como carga para o polipropileno (PP). Compósitos de PP com 10, 15 e 20% em massa do resíduo foram processados em extrusora de rosca dupla e moldados por injeção. Os compósitos moldados foram caracterizados por microscopia eletrônica de varredura (MEV), análises térmicas (DSC e TGA), ensaios mecânicos (tração, flexã...

  5. El fenómeno de la pobreza juvenil: ¿hay diferencias relevantes entre Comunidades Autónomas?

    Directory of Open Access Journals (Sweden)

    Cecilia Albert

    2013-01-01

    Full Text Available Este artículo analiza la variabilidad en el fenómeno de la pobreza de los jóvenes entre Comunidades Autónomas españolas. Utilizando la Encuesta de Condiciones de Vida se estima un modelo logit multinivel de efectos aleatorios. Los resultados apuntan a variaciones entre Comunidades Autónomas en la pobreza por el dispar impacto de la edad, el capital humano, las formas de convivencia, el número de hijos, la nacionalidad y la crisis económica. Las variables incorporadas en el análisis no recogen toda la variabilidad regional, a la que puede contribuir también la estructura productiva o las prestaciones sociales de cada Comunidad Autónoma.

  6. Identification of Open Stomata1-Interacting Proteins Reveals Interactions with Sucrose Non-fermenting1-Related Protein Kinases2 and with Type 2A Protein Phosphatases That Function in Abscisic Acid Responses.

    Science.gov (United States)

    Waadt, Rainer; Manalansan, Bianca; Rauniyar, Navin; Munemasa, Shintaro; Booker, Matthew A; Brandt, Benjamin; Waadt, Christian; Nusinow, Dmitri A; Kay, Steve A; Kunz, Hans-Henning; Schumacher, Karin; DeLong, Alison; Yates, John R; Schroeder, Julian I

    2015-09-01

    The plant hormone abscisic acid (ABA) controls growth and development and regulates plant water status through an established signaling pathway. In the presence of ABA, pyrabactin resistance/regulatory component of ABA receptor proteins inhibit type 2C protein phosphatases (PP2Cs). This, in turn, enables the activation of Sucrose Nonfermenting1-Related Protein Kinases2 (SnRK2). Open Stomata1 (OST1)/SnRK2.6/SRK2E is a major SnRK2-type protein kinase responsible for mediating ABA responses. Arabidopsis (Arabidopsis thaliana) expressing an epitope-tagged OST1 in the recessive ost1-3 mutant background was used for the copurification and identification of OST1-interacting proteins after osmotic stress and ABA treatments. These analyses, which were confirmed using bimolecular fluorescence complementation and coimmunoprecipitation, unexpectedly revealed homo- and heteromerization of OST1 with SnRK2.2, SnRK2.3, OST1, and SnRK2.8. Furthermore, several OST1-complexed proteins were identified as type 2A protein phosphatase (PP2A) subunits and as proteins involved in lipid and galactolipid metabolism. More detailed analyses suggested an interaction network between ABA-activated SnRK2-type protein kinases and several PP2A-type protein phosphatase regulatory subunits. pp2a double mutants exhibited a reduced sensitivity to ABA during seed germination and stomatal closure and an enhanced ABA sensitivity in root growth regulation. These analyses add PP2A-type protein phosphatases as another class of protein phosphatases to the interaction network of SnRK2-type protein kinases.

  7. Activation of the jasmonic acid pathway by depletion of the hydroperoxide lyase OsHPL3 reveals crosstalk between the HPL and AOS branches of the oxylipin pathway in rice.

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    Xiaoqiang Liu

    Full Text Available The allene oxide synthase (AOS and hydroperoxide lyase (HPL branches of the oxylipin pathway, which underlie the production of jasmonates and aldehydes, respectively, function in plant responses to a range of stresses. Regulatory crosstalk has been proposed to exist between these two signaling branches; however, there is no direct evidence of this. Here, we identified and characterized a jasmonic acid (JA overproduction mutant, cea62, by screening a rice T-DNA insertion mutant library for lineages that constitutively express the AOS gene. Map-based cloning was used to identify the underlying gene as hydroperoxide lyase OsHPL3. HPL3 expression and the enzyme activity of its product, (E-2-hexenal, were depleted in the cea62 mutant, which resulted in the dramatic overproduction of JA, the activation of JA signaling, and the emergence of the lesion mimic phenotype. A time-course analysis of lesion formation and of the induction of defense responsive genes in the cea62 mutant revealed that the activation of JA biosynthesis and signaling in cea62 was regulated in a developmental manner, as was OsHPL3 activity in the wild-type plant. Microarray analysis showed that the JA-governed defense response was greatly activated in cea62 and this plant exhibited enhanced resistance to the T1 strain of the bacterial blight pathogen Xanthomonasoryzaepvoryzae (Xoo. The wounding response was attenuated in cea62 plants during the early stages of development, but partially recovered when JA levels were elevated during the later stages. In contrast, the wounding response was not altered during the different developmental stages of wild-type plants. These findings suggest that these two branches of the oxylipin pathway exhibit crosstalk with regards to biosynthesis and signaling and cooperate with each other to function in diverse stress responses.

  8. Assessment of CD4+ T cell responses to glutamic acid decarboxylase 65 using DQ8 tetramers reveals a pathogenic role of GAD65 121-140 and GAD65 250-266 in T1D development.

    Directory of Open Access Journals (Sweden)

    I-Ting Chow

    Full Text Available Susceptibility to type 1 diabetes (T1D is strongly associated with MHC class II molecules, particularly HLA-DQ8 (DQ8: DQA1*03:01/DQB1*03:02. Monitoring T1D-specific T cell responses to DQ8-restricted epitopes may be key to understanding the immunopathology of the disease. In this study, we examined DQ8-restricted T cell responses to glutamic acid decarboxylase 65 (GAD65 using DQ8 tetramers. We demonstrated that GAD65 121-140 and GAD65 250-266 elicited responses from DQ8+ subjects. Circulating CD4+ T cells specific for these epitopes were detected significantly more often in T1D patients than in healthy individuals after in vitro expansion. T cell clones specific for GAD65 121-140 and GAD65 250-266 carried a Th1-dominant phenotype, with some of the GAD65 121-140-specific T cell clones producing IL-17. GAD65 250-266-specific CD4+ T cells could also be detected by direct ex vivo staining. Analysis of unmanipulated peripheral blood mononuclear cells (PBMCs revealed that GAD65 250-266-specific T cells could be found in both healthy and diabetic individuals but the frequencies of specific T cells were higher in subjects with type 1 diabetes. Taken together, our results suggest a proinflammatory role for T cells specific for DQ8-restricted GAD65 121-140 and GAD65 250-266 epitopes and implicate their possible contribution to the progression of T1D.

  9. La fibra óptica y el fenómeno no lineal mezcla de cuarta onda

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    Fabián Gómez López

    2015-12-01

    Full Text Available RESUMEN Para aprovechar de mejor manera el ancho de banda que tiene la fibra óptica, los sistemas de comunicaciones ópticos han tenido que aumentar la potencia de transmisión de las señales para poder transportar a grandes distancias la información. Debido a lo anterior, comienzan a producirse ciertos fenómenos ópticos no lineales como la mezcla de cuarta onda (Four Wave Mixing, FWM, que degradan la señal de información. En este documento se realiza un estado del arte de la fibra óptica y un estudio del fenómeno no lineal FWM, que se genera cuando dos o más señales ópticas se propagan en la fibra, lo cual conlleva a una mezcla de señales que puede generar nuevos componentes de interferencia de la señal óptica transmitida. ABSTRACT To make better use of the bandwidth that has the optical fiber, optical communications systems have had to increase the transmission power of signals to transport information over long distances. Because of this, certain nonlinear optical phenomena such as four wave mixing (Four Wave Mixing, FWM, which degrade the information signal begin to occur. Herein a state of the art of optical fiber and a study of the nonlinear FWM phenomenon, which is generated when two or more optical signals propagating in the fiber takes place, which leads to a mixture of signals that can generate new components interference of the transmitted optical signal.

  10. Effects of experimental water table and temperature manipulations on ecosystem CO2 fluxes in an Alaskan rich fen

    Science.gov (United States)

    Chivers, M.R.; Turetsky, M.R.; Waddington, J.M.; Harden, J.W.; McGuire, A.D.

    2009-01-01

    Peatlands store 30% of the world's terrestrial soil carbon (C) and those located at northern latitudes are expected to experience rapid climate warming. We monitored growing season carbon dioxide (CO2) fluxes across a factorial design of in situ water table (control, drought, and flooded plots) and soil warming (control vs. warming via open top chambers) treatments for 2 years in a rich fen located just outside the Bonanza Creek Experimental Forest in interior Alaska. The drought (lowered water table position) treatment was a weak sink or small source of atmospheric CO2 compared to the moderate atmospheric CO2 sink at our control. This change in net ecosystem exchange was due to lower gross primary production and light-saturated photosynthesis rather than increased ecosystem respiration. The flooded (raised water table position) treatment was a greater CO2 sink in 2006 due largely to increased early season gross primary production and higher light-saturated photosynthesis. Although flooding did not have substantial effects on rates of ecosystem respiration, this water table treatment had lower maximum respiration rates and a higher temperature sensitivity of ecosystem respiration than the control plot. Surface soil warming increased both ecosystem respiration and gross primary production by approximately 16% compared to control (ambient temperature) plots, with no net effect on net ecosystem exchange. Results from this rich fen manipulation suggest that fast responses to drought will include reduced ecosystem C storage driven by plant stress, whereas inundation will increase ecosystem C storage by stimulating plant growth. ?? 2009 Springer Science+Business Media, LLC.

  11. Compostos fenólicos totais e antocianinas em suco de uva Total phenolics and anthocyanins in grape juice

    Directory of Open Access Journals (Sweden)

    Cassia R. Malacrida

    2005-12-01

    Full Text Available As concentrações de compostos fenólicos totais e antocianinas em sucos de uva reconstituídos e simples, de diferentes marcas, disponíveis no comércio varejista da região metropolitana de Belo Horizonte (Minas Gerais foram quantificadas. Também se determinou a contribuição das antocianinas poliméricas à cor e o índice de degradação das antocianinas. Os teores de compostos fenólicos totais variaram entre 0,27 e 2,41 g/L e as concentrações de antocianinas de 1,17 a 66,80 mg/L. Foram observadas diferenças significativas (Teste de Duncan, pTotal phenolics and anthocyanins contents were quantified in simple and reprocessed grape juices of different brands, commercially available in Belo Horizonte (Minas Gerais, Brazil metropolitan area. The contribution of polymeric anthocyanins to color and the anthocyanins degradation index were also determined. Total phenolics levels varied from 0,27 to 2,41 g/L and anthocyanin concentrations from 1,17 to 66,80 mg/L. Significant differences were found (Duncan's test, p<0,05 in total phenolic and anthocyanin concentrations among different brands of reprocessed grape juice as well as the simple juice. The percent contribution of polymeric anthocyanins to color also varied significantly among different brands, the simple grape juice showing a higher percentage (81,6% than the reprocessed one (77,5%. The latter presented total mean value of anthocyanins degradation (3,92 higher than the former one (3,44.

  12. Jogos de Empresas: Abordagens ao Fenômeno, Perspectivas Teóricas e Metodológicas

    Directory of Open Access Journals (Sweden)

    Valdete de Oliveira Mrtvi

    2017-01-01

    Full Text Available Os jogos de empresas, além de utilizados no processo de ensino, também são explorados como ferramentas de pesquisa, conforme Gentry, Tice, Robertson e Gentry (1984. Este estudo, de natureza qualitativa e quantitativa, descritivo quanto aos objetivos, e caracterizado como revisão integrativa no tocante ao método, trata do seguinte problema de pesquisa: Qual o perfil da pesquisa acadêmica brasileira sobre jogos de empresas considerando a abordagem ao fenômeno e as perspectivas teóricas e metodológicas? Foram analisados 226 artigos extraídos de periódicos online, do indexador Spell e anais de eventos. Como resultado, é proposta uma tipologia para classificação das pesquisas em jogos de empresas, considerando a abordagem ao fenômeno de pesquisa e os eixos temáticos. Constatou-se a predominância de estudos que têm as simulações como objeto de pesquisa - SCOPE (77,9% -, enquanto 22,1% utilizam os jogos de empresas como ambiente de pesquisa - SCAPE. Verificou-se que 38,5% dos estudos não mencionam quaisquer das classificações metodológicas analisadas. Discute-se algumas fragilidades metodológicas identificadas nas pesquisas da área. Apesar de as classificações não serem determinantes para a qualidade de um estudo, representam importante indicador da consistência do processo de reflexão e da coesão da investigação.

  13. Revictimización un fenómeno invisibilizado en las instituciones Revictimization an invisiblelized phenomena in institutions

    Directory of Open Access Journals (Sweden)

    Berenice Smith Bonilla

    2007-03-01

    Full Text Available El presente trabajo de investigación sobre la revictimiación institucional pone de manifiesto la existencia de dicho fenómeno dentro del sistema judicial. Se analizan las causas de esta situación la cual aparenta no tener la debida cobertura del sistema ni la de los propios funcionarios que laboran en tal situación. Se hace una exposición de motivos que explica el fenómeno que incluye las políticas existentes, las estrategias de capacitación, difusión y consistencia. Además se estudia la existencia de la Oficina de Atención a la Víctima del Delito desde su iniciativa, la cual catapulta la figura de la víctima a un lugar hasta entonces negado, sin que su actuar trascienda al ámbito requerido por razones que se analizan. En las conclusiones se brindan recomendaciones pertinentes para quienes están sufriendo como victimas por su labor.This investigation about institutional revictimization demonstrates the existence of this phenomenon within the judicial system. The causes of this situation are analyzed, that seems not to have the appropriate coverage from the system nor from the employees of the institutions. An exposition of the different motives is done to explain the phenomenon that includes current policies, capacitating strategies, diffusion and consistency. Also the existence of the Attention to Victim of Crime Office is studied from its initiative, which catapults the victim figure to a previously denied place. As conclusions, some recommendations are brought for those who are suffering as victims.

  14. Sentimentos do adolescente relacionados ao fenômeno BULLYING: possibilidades para a Assistência de Enfermagem nesse contexto

    Directory of Open Access Journals (Sweden)

    Agnes Schutz de Oliveira

    2006-04-01

    Full Text Available O bullying é um fenômeno devastador podendo vir a afetar a auto-estima e a saúde mental dos adolescentes. Geralmente ocorre quando o adolescente é mais suscetível ou vulnerável às agressões verbais ou morais que lhes causam angústia e dor, principalmente quando ocorrido em ambiente escolar traduzindo-se como uma forma de exclusão social. Pode desencadear alguns problemas de saúde tais como a anorexia, bulimia, depressão, ansiedade e até mesmo o suicídio. A enfermagem, pautada com princípios de prevenir agravos de diversos males, preocupa-se também com esta intercorrência traumática na adolescência. O objetivo deste estudo foi identificar sentimentos que possam estar relacionados com o bullying em adolescentes alunos de 5ª a 8ª séries. Tratou-se de uma pesquisa descritiva de abordagem qualitativa, realizada em uma escola de segmento religioso conveniada com o estado. A coleta de dados ocorreu auxiliada por entrevistas gravadas, posteriormente transcritas e submetidas à análise temática. Os resultados mostraram que os sentimentos relacionados ao fenômeno são múltiplos e variados, sendo categorizados como aspectos de caráter positivo, aspectos de caráter negativo e aspectos de caráter necessário.

  15. Comparación del contenido fenólico, capacidad antioxidante y actividad antiinflamatoria de infusiones herbales comerciales Comparison of phenolic content, antioxidant capacity and anti-inflamatory activity of commercial herbal infusions

    Directory of Open Access Journals (Sweden)

    Erika Elizabeth Muñoz-Velázquez

    2012-06-01

    Full Text Available En la actualidad, hay un incremento en el consumo de infusiones debido a sus propiedades benéficas, las cuales se atribuyen a la presencia de compuestos fenólicos. Por lo anterior, el objetivo de este estudio fue evaluar el contenido fenólico, la capacidad antioxidante y la actividad antiinflamatoria de infusiones comerciales de hierbabuena (Mentha piperita L., limón (Cymbopogon citratos, manzanilla (Matricaria chamomilla L., árnica (Heterotheca inuloides y boldo (Peumus boldus Molina obtenidas en un supermercado en 2009. El contenido de fenoles y la capacidad antioxidante se determinaron por técnicas espectrofotométricas. Adicionalmente, la identificación y cuantificación de compuestos fenólicos también se llevó a cabo por HPLC. La actividad antiinflamatoria se evaluó mediante la inhibición de la enzima ciclooxigenasa-2 (COX-2. La infusión de boldo presentó el mayor contenido de compuestos fenólicos y la mayor capacidad antioxidante medida por la técnicas ABT, seguida de las infusiones de hierbabuena por el m��todo de FRAP. En las infusiones evaluadas se identificaron diez diferentes compuestos, encontrándose en mayor concentración los compuestos catequina, epigalocatequina galato, ácido rosmarínico y eriocitrina. En cuanto a la capacidad inhibitoria sobre COX-2, las muestras de manzanilla y limón presentaron los mayores porcentajes de inhibición, seguida de la infusión de boldo. En general, los resultados sugieren que las infusiones comerciales de boldo y hierbabuena muestran propiedades biológicas con beneficios potenciales a la salud.Actually there is an increase on infusion consumption due their beneficial properties, which are attributable to the presence of phenolic compounds. By this reason, the aim of this study was to assess phenolic content, antioxidant capacity and anti-inflammatory capacity of commercial infusions of peppermint (Mentha piperita L., lemon grass (Cymbopogon citratos, chamomile (Matricaria

  16. How a regional aquifer, a local aquifer and an oxbow lake impact on hydrological and biogeochemical processes in ariparian fen-meadow ecosystem

    DEFF Research Database (Denmark)

    Hoffmann, Carl Christian; Pedersen, Morten Lauge; Rasmussen, K. R.

    2009-01-01

    The groundwater flow pattern through a riparian fen-meadow was investigated by use of piezometer transects, soil survey, measurements of piezometric heads and measurements of hydraulic conductivity. Groundwater was sampled from piezometers and analysed for nitrate-N. Water balances and nitrate-N ...

  17. Parâmetros climáticos e variação de compostos fenólicos em cevada

    Directory of Open Access Journals (Sweden)

    Aline Sobreira Bezerra

    2013-09-01

    Full Text Available Objetivou-se quantificar os compostos fenólicos em extrato hidroetanólico de grãos das cultivares de cevada ('BRS Lagoa' e 'MN 743' em dois anos consecutivos de cultivo (2005 e 2006, avaliando a influência dos fatores climáticos nesse conteúdo. Os compostos fenólicos totais foram quantificados pelo método de Folin-Ciocalteau e os teores de rutina e ácidos cafeico e ferúlico por CLAE em fase reversa. O conteúdo de compostos fenólicos totais variou de 0,97 a 1,59 mg AG g-1 de cevada e os fatores climáticos durante o período de plantio e colheita influenciaram no conteúdo. Foram identificados e quantificados nessas cultivares rutina, ácido cafeico e ácido ferúlico. A avaliação dos fatores climáticos no conteúdo de compostos fenólicos em cevada é de grande interesse, visando a sua importância nutricional e recomendação de cultivares com conteúdos expressivos de compostos bioativos.

  18. Para Além do Estado e do Mercado: A Dádiva no Fenômeno dos Sem-Abrigo

    Directory of Open Access Journals (Sweden)

    João Aldeia

    2014-03-01

    Full Text Available Las reflexiones sobre el fenómeno de los sin techo tienden a reproducir las ausencias que el paradigma del don identifica en el pensamiento sobre las sociedades modernas occidentales. Recurrentemente, se considera al Estado y al mercado como las únicas esferas de regulación social y se los interpreta como los espacios de donde derivan las causas estructurales y las posibles soluciones para el fenómeno. Ello no permite una comprensión completa del tema y tampoco una reflexión consistente sobre los modos de minimizar las injusticias de la vida en la calle. Pensar sobre el fenómeno por medio del paradigma del don es relevante porque permite identificar la habitual invisibilización de las relaciones interpersonales no oficiales que caracterizan la vida en la calle, posibilitando, a su vez, la revalorización de estas interacciones en el debate sobre el fenómeno de los sin techo.

  19. El fenómeno de El Niño -la oscilación del sur- y la Arqueología del occidente de Cuba

    Directory of Open Access Journals (Sweden)

    Alexis Rives Pantoja

    2011-06-01

    Full Text Available Se estudian diversas evidencias arqueológicas, especialmente de materiales cerámicos, en asentamientos establecidos en el occidente de Cuba, a través de las cuales se pueden observar las problemáticas ambientales y la influencia del fenómeno El Niño en el pasado aborigen.

  20. Understanding the long term ecosystem stability of a fen mire by analyzing subsurface geology, eco-hydrology and nutrient stoichiometry - Case study of the Rospuda valley (NE Poland)

    NARCIS (Netherlands)

    Jabłońska, Ewa; Falkowski, Tomasz; Chormański, Jarosław; Jarzombkowski, Filip; Kłosowski, Stanisław; Okruszko, Tomasz; Pawlikowski, Paweł; Theuerkauf, Martin; Wassen, Martin J.; Kotowski, Wiktor

    2014-01-01

    We explored the background of differences in long-term stability between two parts in an undisturbed mire system (Rospuda fen, NE Poland). We re-constructed the Holocene history of the mire and compared it with current vegetation, water level dynamics, water chemistry and nutrient availability in tw

  1. Compuestos fenólicos y flavonoides como marcadores bioquímicos de la respuesta a estrés abiótico en plantas tolerantes

    OpenAIRE

    CALATAYUD VAELLO, PAU

    2011-01-01

    Calatayud Vaello, P. (2010). Compuestos fenólicos y flavonoides como marcadores bioquímicos de la respuesta a estrés abiótico en plantas tolerantes. http://hdl.handle.net/10251/9179. Archivo delegado

  2. Desarrollo de técnicas de extracción y análisis de antocianinas y compuestos fenólicos en Jaboticaba (Myrciaria Cauliflora)

    OpenAIRE

    Mera Morillo, Celia

    2015-01-01

    Desarrollo de técnicas de extracción mediante ultrasonidos y mediante fluidos presurizados para así, obtener las condiciones óptimas de extracción de las antocianinas mayoritarias y compuestos fenólicos totales presentes en la jaboticaba

  3. Magnetic properties of the 2D Fen core Xm (X = C, N, O, Cl, S and F) shell clusters embedded in graphene

    Science.gov (United States)

    Zhao, Ming-Yu; Zhao, Ru-Meng; Li, Wei; Ma, Ya-Qiang; Wang, Tian-Xing; Dai, Xian-Qi

    2017-01-01

    Utilizing first-principle calculations, the structural, electronic and magnetic properties of monolayer graphene embedded with Fen/Xm (X = C, N, O, Cl, S and F) core/shell clusters are investigated, where n = 1, 2, 3 and m = 4, 6, respectively. We find that the graphene embedding with the Fen/Xm core/shell clusters are magnetic except the Fe/S4, Fe2/C4 and Fe3/Cl6 core/shell clusters. The graphene embedding with the Fe3/F6 core/shell cluster has the largest magnetic moment in these systems. Magnetism for Fen/Xm core/shell clusters embedded in monolayer graphene can be ascribed to the ferromagnetic coupling between the Fe atoms. Our calculations demonstrate that Fe atoms are successfully isolated at various C, N, O, Cl, S and F shells in graphene to preserve the high-spin state. On the other hand, the high-spin state is also effectively controlled by the amount of Fe atoms. The electron spin can be stored in magnetic thin film, lithographically prepared quantum dots, and electromagnetic traps. The Fen/Xm core/shell clusters embedded in graphene can be considered to have potential applications in nanoelectronics, spintronics and magnetic storage devices.

  4. The Fatty Acid Profile Analysis of Cyperus laxus Used for Phytoremediation of Soils from Aged Oil Spill-Impacted Sites Revealed That This Is a C18:3 Plant Species.

    Directory of Open Access Journals (Sweden)

    Noemí Araceli Rivera Casado

    Full Text Available The effect of recalcitrant hydrocarbons on the fatty acid profile from leaf, basal corm, and roots of Cyperus laxus plants cultivated in greenhouse phytoremediation systems of soils from aged oil spill-impacted sites containing from 16 to 340 g/Kg total hydrocarbons (THC was assessed to investigate if this is a C18:3 species and if the hydrocarbon removal during the phytoremediation process has a relationship with the fatty acid profile of this plant. The fatty acid profile was specific to each vegetative organ and was strongly affected by the hydrocarbons level in the impacted sites. Leaf extracts of plants from uncontaminated soil produced palmitic acid (C16, octadecanoic acid (C18:0, unsaturated oleic acids (C18:1-C18:3, and unsaturated eichosanoic (C20:2-C20:3 acids with a noticeable absence of the unsaturated hexadecatrienoic acid (C16:3; this finding demonstrates, for the first time, that C. laxus is a C18:3 plant. In plants from the phytoremediation systems, the total fatty acid contents in the leaf and the corm were negatively affected by the hydrocarbons presence; however, the effect was positive in root. Interestingly, under contaminated conditions, unusual fatty acids such as odd numbered carbons (C15, C17, C21, and C23 and uncommon unsaturated chains (C20:3n6 and C20:4 were produced together with a remarkable quantity of C22:2 and C24:0 chains in the corm and the leaf. These results demonstrate that weathered hydrocarbons may drastically affect the lipidic composition of C. laxus at the fatty acid level, suggesting that this species adjusts the cover lipid composition in its vegetative organs, mainly in roots, in response to the weathered hydrocarbon presence and uptake during the phytoremediation process.

  5. The Fatty Acid Profile Analysis of Cyperus laxus Used for Phytoremediation of Soils from Aged Oil Spill-Impacted Sites Revealed That This Is a C18:3 Plant Species.

    Science.gov (United States)

    Rivera Casado, Noemí Araceli; Montes Horcasitas, María del Carmen; Rodríguez Vázquez, Refugio; Esparza García, Fernando José; Pérez Vargas, Josefina; Ariza Castolo, Armando; Ferrera-Cerrato, Ronald; Gómez Guzmán, Octavio; Calva Calva, Graciano

    2015-01-01

    The effect of recalcitrant hydrocarbons on the fatty acid profile from leaf, basal corm, and roots of Cyperus laxus plants cultivated in greenhouse phytoremediation systems of soils from aged oil spill-impacted sites containing from 16 to 340 g/Kg total hydrocarbons (THC) was assessed to investigate if this is a C18:3 species and if the hydrocarbon removal during the phytoremediation process has a relationship with the fatty acid profile of this plant. The fatty acid profile was specific to each vegetative organ and was strongly affected by the hydrocarbons level in the impacted sites. Leaf extracts of plants from uncontaminated soil produced palmitic acid (C16), octadecanoic acid (C18:0), unsaturated oleic acids (C18:1-C18:3), and unsaturated eichosanoic (C20:2-C20:3) acids with a noticeable absence of the unsaturated hexadecatrienoic acid (C16:3); this finding demonstrates, for the first time, that C. laxus is a C18:3 plant. In plants from the phytoremediation systems, the total fatty acid contents in the leaf and the corm were negatively affected by the hydrocarbons presence; however, the effect was positive in root. Interestingly, under contaminated conditions, unusual fatty acids such as odd numbered carbons (C15, C17, C21, and C23) and uncommon unsaturated chains (C20:3n6 and C20:4) were produced together with a remarkable quantity of C22:2 and C24:0 chains in the corm and the leaf. These results demonstrate that weathered hydrocarbons may drastically affect the lipidic composition of C. laxus at the fatty acid level, suggesting that this species adjusts the cover lipid composition in its vegetative organs, mainly in roots, in response to the weathered hydrocarbon presence and uptake during the phytoremediation process.

  6. Fenótipo cintura hipertrigliceridêmica: associação com alterações metabólicas em adolescentes

    Directory of Open Access Journals (Sweden)

    Maria Ester P. da Conceição-Machado

    2013-02-01

    Full Text Available OBJETIVO: O presente estudo objetivou identificar a prevalência do fenótipo cintura hipertrigliceridêmica (CHT e avaliar sua associação com alterações metabólicas em adolescentes de baixa condição econômica. MÉTODO: Estudo transversal com amostra probabilística de 1.076 adolescentes entre 11 e 17 anos, de ambos os sexos, estudantes de escolas públicas. Os participantes foram submetidos à avaliação antropométrica (peso, altura e circunferência da cintura e à dosagem dos níveis de colesterol total, LDL-C, HDL-C, colesterol não HDL, triglicérides (TG e glicemia de jejum. Foram obtidas informações referentes às condições econômicas das famílias dos participantes.O fenótipo CHT foi definido pela presença simultânea da circunferência da cintura aumentada (> percentil 90 por idade e sexo e dos níveis séricos de triglicérides elevados (> 100 mg/dL. A análise de regressão logística foi utilizada para avaliação das associações de interesse. RESULTADOS: A prevalência do fenótipo CHT foi de 7,2% entre os adolescentes, sendo mais elevada na presença de obesidade (63,4%, do colesterol não HDL (16,6% e do LDL-C (13,7% altos. A análise bivariada indicou que, das variáveis metabólicas, apenas a glicemia não se associou ao fenótipo CHT. A análise multivariada, ajustada por sexo e idade, indicou que o fenótipo CHT se associou positivamente com o colesterol não HDL alto (odds ratio, 7,0; IC 95% 3,9-12,6 e com o HDL-C baixo (odds ratio, 2,7; IC 95%, 1,5-4,8. CONCLUSÕES: Este estudo mostrou que o fenótipo CHT se associou com um perfil lipídico aterogênico e sugere esse fenótipo como uma ferramenta de screening que pode ser utilizada para identificar adolescentes com alterações metabólicas.

  7. Composição fenólica de ligninas dioxano determinadas pela reação oxidativa com o nitrobenzeno

    Directory of Open Access Journals (Sweden)

    Fukushima Romualdo Shigueo

    2003-01-01

    Full Text Available A correta quantificação da concentração de lignina em plantas forrageiras, pelo método espectrofotométrico, pressupõe a existência de um padrão de referência. Um padrão de referência deve ter composição fenólica semelhante à da lignina da parede celular. O objetivo deste trabalho foi verificar se ligninas extraídas com solução ácida de dioxano para serem utilizadas como padrão de referência, apresentariam variação na composição fenólica da mesma maneira que a lignina da parede celular. Amostras de parede celular de "bromegrass", milho e trevo-vermelho foram submetidas ao método para extração de ligninas com solução ácida de dioxano. A composição fenólica das ligninas foi analisada mediante oxidação alcalina pelo nitrobenzeno com posterior separação dos componentes monoméricos via HPLC. As ligninas extraídas confirmaram a existência de variação na composição fenólica da mesma maneira às ligninas intactas presentes na parede celular e de substancial presença de ácidos cinâmicos nas ligninas de gramíneas. No que diz respeito à composição fenólica, ligninas extraídas com solução ácida de dioxano podem ser consideradas potenciais padrões de referência paras as análises espectrofotométricas.

  8. Environmental and Physiographic Controls on Inter-Growing Season Variability of Carbon Dioxide and Water Vapour Fluxes in a Minerotrophic Fen

    Science.gov (United States)

    van der Kamp, G.; Sonnentag, O.; Chen, J. M.; Barr, A.; Hedstrom, N.; Granger, R.

    2008-12-01

    The interaction of fens with groundwater is spatially and temporally highly variable in response to meteorological conditions, resulting in frequent changes of groundwater fluxes in both vertical and lateral directions (flow reversals) across the mineral soil-peat boundary. However, despite the importance of the topographic and hydrogeological setting of fens, no study has been reported in the literature that explores a fen's atmospheric CO2 and energy flux densities under contrasting meteorological conditions in response to its physiographic setting. In our contribution we report four years of growing season eddy covariance and supporting measurements from the Canada Fluxnet-BERMS fen (formerly BOREAS southern peatland) in Saskatchewan, Canada. We first analyze hydrological data along two piezometer transects across the mineral soil-peat boundary with the objective of assessing changes in water table configuration and thus hydraulic gradients, indicating flow reversals, in response to dry and wet meteorological conditions. Next we quantify and compare growing season totals and diurnal and daily variations in evapotranspiration (ET) and net ecosystem exchange (NEE) and its component fluxes gross ecosystem productivity (GPP) and terrestrial ecosystem respiration (TER) to identify their controls with a major focus on water table depth. While ET growing season totals were similar (~ 310 mm) under dry and wet meteorological conditions, the CO2 sink- source strength of Sandhill fen varied substantially from carbon neutral (NEE = -2 [+-7] g C m-2 per growing season) under dry meteorological condition (2003) to a moderate CO2- sink with NEE ranging between 157 [+- 10] and 190 [+- 11] g C m-2 per growing season under wet meteorological conditions (2004, 2005, and 2006). Using a process-oriented ecosystem model, BEPS-TerrainLab, we investigate how different canopy components at Sandhill contribute to total ET and GPP, and thus water use efficiency, under dry and wet

  9. Produção de mudas de cultivares de alface utilizando duas espumas fenólicas em Altamira, Pará

    Directory of Open Access Journals (Sweden)

    Alzirio Lino Couto

    2015-06-01

    Full Text Available O sucesso de qualquer produção comercial de hortaliças inicia-se com a produção de mudas. A espuma fenólica tem se mostrado um interessante e prático substrato para este processo. A utilização deste produto depende de uma lavagem precedente para reduzir a acidez. Porém, já é possível encontrar à venda espumas fenólicas com pH próximo. Por isso o objetivo deste trabalho foi avaliar a produção de mudas de cultivares de alface utilizando duas espumas fenólicas em Altamira, Pará. O delineamento constou de um esquema fatorial 2 (substratos x 6 (cultivares. Os dois substratos foram as espumas fenólicas Green Up®, com pH 6.0 (± 0.5., e a outra com pH 2.6 (± 0.5. As cultivares avaliadas foram: Alcione, Amanda, Lucy Brown, Caipira, Multiblond 3 e Solaris. Foi avaliada porcentagem de germinação, índice de velocidade de emergência, altura da planta e número de folhas. Houve diferença significativa para altura da planta em função dos substratos testados. A porcentagem de germinação mais elevada foi obtida com a espuma fenólica sem tratamento. A cultivar Caipira foi a que teve o menor desempenho na germinação. Para todas as variáveis analisadas, a cultivar Lucy Brown apresentou os melhores resultados em ambos os substratos.

  10. Avaliação da influência de substâncias fenólicas e carotenoides na anomalia do epicarpo da goiaba, "anelamento"

    Directory of Open Access Journals (Sweden)

    Taiji Watanabe

    2011-03-01

    Full Text Available A anomalia do epicarpo da goiaba, comumente relatada por agricultores e técnicos como o "anelamento juvenil da goiaba", tem causado preocupação devido à desinformação sobre o assunto. O objetivo deste estudo foi analisar quimicamente as concentrações de substâncias fenólicas e carotenoides na região do epicarpo de goiabas afetadas pelo "anelamento", visando a caracterizar essa anomalia previamente relatada. Foram analisadas substâncias fenólicas (taninos, flavonas/flavonóis, antocianinas e fenóis totais e carotenoides em epicarpos de frutos verdes e maduros de goiabeiras cv. Paluma, com e sem anomalia. O delineamento experimental adotado foi o inteiramente casualizado, sendo estabelecidos seis tratamentos com o epicarpo dos frutos maduro sem anomalia na região inferior (FMSI; frutos maduros sem injuria na região superior (FMSS; frutos verdes sem anomalia na região inferior (FVSI; frutos verdes sem anomalia na região superior (FVSS; frutos verdes com anomalia na região inferior (FVCI; frutos verdes com anomalia na região superior (FVCS. Dentre as substâncias analisadas, os carotenoides, os taninos e os fenóis totais mostram indicativos para a caracterização do anelamento. Tanto substâncias fenólicas quanto carotenoides apresentam propriedades antioxidantes e, dessa forma, poderiam estar relacionadas à defesa antioxidante causada por um fator de estresse ainda desconhecido, que promove o "anelamento" característico apresentado pelas goiabas.

  11. The preferential growth of branched GDGT source microorganisms under aerobic conditions in peat revealed by stable isotope probing experiments

    Science.gov (United States)

    Huguet, Arnaud; Meador, Travis B.; Laggoun-Défarge, Fatima; Könneke, Martin; Derenne, Sylvie; Hinrichs, Kai-Uwe

    2016-04-01

    , whereas corresponding rates in the anaerobic acrotelm incubations were more than an order of magnitude slower (< 3 ng cm-3 y-1). Production rates of bacterial fatty acids approached or exceeded 1 μg cm-3 y-1 in both aerobic and anaerobic incubations, and were therefore much higher than those of brGDGTs. This suggests that the brGDGT producers are a minor constituent of the microbial community in Sphagnum-dominated peatlands or brGDGTs are a small component of the microbial cell membrane in comparison to fatty acids, despite the typically high brGDGT concentrations observed in peat. In conclusion, our results reveal that brGDGT source microorganisms preferentially grow under oxic to sub-oxic conditions, likely as facultative anaerobes. We show for the first time that these microorganisms are especially active at the peat surface, in contrast to the deeper layers, implying that the high abundance of brGDGTs observed in the catotlem should result from the accumulation of the brGDGTs actively produced in the acrotelm. Reference Weijers, J.W.H., Wiesenberg, G.L.B., Bol, R., Hopmans, E.C., Pancost, R.D., 2010. Biogeosciences 7, 2959-2973.

  12. La dictadura militar en Grecia (1967- 1974. ¿Cómo enfocar el fenómeno autoritario?

    Directory of Open Access Journals (Sweden)

    Georges D. CONTOGEORGIS

    2010-02-01

    Full Text Available RESUMEN: La Dictadura de los Coroneles es abordada como un fenómeno inherente al déficit democrático, no tanto de la sociedad griega, sino del sistema internacional. El hecho de que la Dictadura Griega se atribuya a valores geoestratégicos y al déficit democrático (p.e. la prohibición del acceso al poder de los partidos políticos no liberales de los líderes de la Guerra Fría está también en sintonía con la diferencia fundamental que lo distingue de las dictaduras de la Península Ibérica. Estas últimas están relacionadas con un mismo fenómeno anterior de la Europa anterior a la Segunda Guerra Mundial y como tales están clasificadas como una parte del proceso de transición que tuvo lugar en el Viejo Continente. Por el contrario, el fenómeno autoritario en el sistema político griego constituye un paréntesis porque la sociedad griega no experimentó la transición del feudalismo a la modernidad y su sistema político fue desde el comienzo (desde 1821 el primero entre los estados-nación con una base representativa asentada sobre el sufragio universal. Todo ello demuestra que las distinciones entre Norte y Sur, relativas a la democracia, están ideológicamente condicionadas y no derivan de conclusiones extraídas del desarrollo político de las sociedades. Palabras clave: Totalitarismo, Dictadura, Déficit democrático, Estado representativo, Guerra Fría, Protesta, Consenso político. ABSTRACT: The Dictatorship of the Colonels is approached as a phenomenon, which is inherent in the democratic deficit, not of Greek society, but of the international system. The fact that the Greek Dictatorship is attributed to geostrategic reasons and to the democratic deficit (e.g. the prohibition of access to power of non-liberal political parties of the leaders of the Cold War is also in line with the fundamental difference, which distinguishes it from dictatorships of the Iberian Peninsula. The latter are related to the same phenomena of

  13. Aspartic acid

    Science.gov (United States)

    Aspartic acid is a nonessential amino acids . Amino acids are building blocks of proteins. "Nonessential" means that our ... this amino acid from the food we eat. Aspartic acid is also called asparaginic acid. Aspartic acid helps ...

  14. Fen Eğitiminde Dijital Teknoloji Ürünü Dinamik Görsel Kullanımı – Fen Bilgisi Öğretmen Adaylarının Algıları

    OpenAIRE

    KAHRAMAN, Sakıp; DEMİR, Yaşar; Nazan DEMİR

    2015-01-01

    Bu çalışmanın amacı, atmosfer ile ilgili çevre problemleri (küresel ısınma, asit yağmurları ve ozon tabakası delinmesi) ve bu problemlerin çözümünde kritik bir role sahip olan yenilenebilir enerji kaynaklarının öğretimi boyunca animasyon, kısa film ve belgesel gibi dijital teknoloji ürünü dinamik görselleri gözlemleyen fen bilgisi öğretmen adaylarının süreç ile ilgili algılarını belirlemektir. Bu temel amaçtan hareketle araştırmanın çalışma grubu, Türkiye’nin batısında bulunan orta büyüklükte...

  15. Avaliação da atividade antioxidante dos compostos fenólicos naturalmente presentes em subprodutos do pseudofruto de caju (Anacardium occidentale L. Evaluation of the Antioxidant Activity of Phenolic Compounds Naturally Contained in By-products of the Cashew Apple (Anacardium occidentale L.

    Directory of Open Access Journals (Sweden)

    Priscila Regina Bolelli Broinizi

    2007-12-01

    Full Text Available O presente trabalho teve como proposta avaliar a capacidade antioxidante do bagaço e do extrato bruto concentrado (EBC do pedúnculo de caju, tendo em vista o seu aproveitamento. O potencial antioxidante dos extratos aquoso (EAq e alcoólico (EAlc e das frações de ácidos fenólicos livres (AFL e esterificadas (solúvel AFS e insolúvel AFI desses subprodutos do pedúnculo de caju clone CCP-76 foi avaliado em sistema beta-caroteno/ácido linoléico, pelo teste de varredura de radical livre [2,2 difenil-1-pricril-hidrazil (DPPH•] e de Rancimat. Além do mais, o conteúdo de fenólicos totais e o perfil de ácidos fenólicos foram determinados usando-se o reagente de Folin-Ciocateau e por cromatografia gasosa, respectivamente. O EAq e a fração AFL dos subprodutos apresentaram o maior conteúdo de fenólicos. As frações de ácidos fenólicos exibiram expressiva atividade antioxidante, superior aos extratos estudados nos sistemas beta-caroteno e DPPH. Entretanto no teste Rancimat, os extratos apresentaram maior proteção à oxidação em relação às frações e ao BHT. Nas frações foram identificados os ácidos gálico, ferúlico, caféico, protocatecuico, quínico, cinâmico, gentíssico, p-cumárico e salicílico, os quais lhes conferem o potencial antioxidante. Estes resultados caracterizaram in vitro o potencial antioxidante do bagaço e do EBC do pedúnculo de caju clone CCP-76.This study aimed to determine the antioxidant capacity of cashew apple pulp and raw concentrated extract. The antioxidant potential of aqueous (EAq and alcoholic (EAlc extracts and of free phenolic acids (FPA and esterified (soluble - SPA and insoluble - IPA fractions of the by-products of the cashew apple clone CCP-76 were evaluated in a beta-carotene-linoleate system by the free radical [2,2-diphenyl-1-picrylhydrazyl (DPPH•] scavenging assay and the Rancimat test. In addition, the total phenolic content and phenolic acid profile were determined using

  16. Precise measurement of the thermal and stellar $^{54}$Fe($n, \\gamma$)$^{55}$Fe cross sections via AMS

    CERN Document Server

    Wallner, Anton; Buczak, Kathrin; Coquard, Laurent; Bichler, Max; Dillmann, Iris; Golser, Robin; Käppeler, Franz; Karakas, Amanda; Kutschera, Walter; Lederer, Claudia; Mengoni, Alberto; Pignatari, Marco; Priller, Alfred; Reifarth, Rene; Steier, Peter; Szentmiklosi, Laszlo

    2016-01-01

    The detection of long-lived radionuclides through ultra-sensitive single atom counting via accelerator mass spectrometry (AMS) offers opportunities for precise measurements of neutron capture cross sections, e.g. for nuclear astrophysics. The technique represents a truly complementary approach, completely independent of previous experimental methods. The potential of this technique is highlighted at the example of the $^{54}$Fe($n, \\gamma$)$^{55}$Fe reaction. Following a series of irradiations with neutrons from cold and thermal to keV energies, the produced long-lived $^{55}$Fe nuclei ($t_{1/2}=2.744(9)$ yr) were analyzed at the Vienna Environmental Research Accelerator (VERA). A reproducibility of about 1% could be achieved for the detection of $^{55}$Fe, yielding cross section uncertainties of less than 3%. Thus, the new data can serve as anchor points to time-of-flight experiments. We report significantly improved neutron capture cross sections at thermal energy ($\\sigma_{th}=2.30\\pm0.07$ b) as well as fo...

  17. Water level, vegetation composition and plant productivity explain greenhouse gas fluxes in temperate cutover fens after inundation

    Directory of Open Access Journals (Sweden)

    M. Minke

    2015-10-01

    Full Text Available Rewetting of temperate continental cutover peatlands generally implies the creation of flooded areas, which are – dependent on water depth – colonized by helophytes such as Eriophorum angustifolium, Carex spp., Typha latifolia or Phragmites australis. Reeds of Typha and Phragmites are reported to be large sources of methane, but data on net CO2 uptake are contradictory for Typha and rare for Phragmites. This paper describes the effect of vegetation, water level and nutrient conditions on greenhouse gas (GHG emissions for representative vegetation types along water level gradients at two rewetted cutover fens (mesotrophic and eutrophic in Belarus. Greenhouse emissions were measured with manual chambers in weekly to few – weekly intervals over a two years period and interpolated by modelling. All sites had negligible nitrous oxide exchange rates. Most sites were carbon sinks and small GHG sources. Methane emissions were generally associated with net ecosystem CO2 uptake. Small sedges were minor methane emitters and net CO2 sinks, while Phragmites australis sites released large amounts of methane and sequestered very much CO2. Variability of both fluxes increased with site productivity. Floating mats composed of Carex tussocks and Typha latifolia were a source for both methane and CO2. We conclude that shallow, stable flooding is a better measure to arrive at low GHG emissions than deep flooding, and that the risk of high GHG emissions consequent on rewetting is larger for eutrophic than for mesotrophic peatlands.

  18. Compostos fenólicos e atividade antioxidante de Leiothrix flavescens (Bong. Ruhland (Eriocaulaceae

    Directory of Open Access Journals (Sweden)

    M. A. SILVA

    2009-01-01

    Full Text Available

    O presente estudo químico foi realizado com extrato metanólico de Leiothrix flavescens (Bong. Ruhland (Eriocaulaceae por HSCCC. Fracionamento do extrato metanólico dos capítulos de L. flavescens por métodos cromatográficos preparativos e identificação das substâncias isoladas por (IV, UV, RMN forneceu as flavonas apigenina, luteolina e 6-metoxiluteolina e o 1,3-di-Oferuloilglicerol. O extrato metanólico de L. flavescens foi avaliado quanto à sua atividade antioxidante utilizando- se o reagente de DPPH, enquanto que a quantificação de fenóis totais foi determinada utilizando-se o reagente de Folin-Ciocalteau. Os resultados evidenciaram que o extrato metanólico dos capítulos L. flavescens possui uma significativa atividade antioxidante. Estes resultados permitiram aprofundar a discussão taxonômica da família Eriocaulaceae. Palavras-chave: Eriocaulaceae; Leiothrix; HSCCC; atividade antioxidante.

  19. Fenómenos fisiopatológicos sistémicos asociados al bruxismo de sueño

    Directory of Open Access Journals (Sweden)

    V. Iturriaga

    2014-12-01

    Full Text Available El bruxismo de sueño (BS se define como un trastorno del movimiento estereotipado que se presenta durante el sueño, caracterizado por rechinamiento y/o apretamiento dentario. Se encuentra dentro de la clasificación internacional de desórdenes de sueño como un trastorno del movimiento asociado a una exagerada actividad muscular masticatoria rítmica. Se reporta una incidencia del 15% al 22% en la población general. Antiguamente se creía que la etiología del BS estaba relacionada con alteraciones oclusales; sin embargo actualmente se piensa que la causa principal está más bien relacionada con alteraciones de sueño, enfermedades del sistema nervioso central, drogas, dolor crónico, alteraciones emocionales, entre otros factores que participarían en su origen. Se ha identificado la presencia de diversos fenómenos fisiopatológicos sistémicos que acontecen durante un episodio de BS, entre los cuales encontramos los microdespertares corticales, alteraciones en el ritmo cardíaco, el tono simpático, la presión arterial, entre otros, sobre los cuales trata esta revisión.

  20. El análisis discursivo de fenómenos de violencia en un corpus de prensa digital

    Directory of Open Access Journals (Sweden)

    Carmen Ávila Martín

    2014-08-01

    Full Text Available Normal 0 21 false false false ES X-NONE X-NONE El análisis del discurso mediático dispone en la actualidad de herramientas que proporcionan análisis empíricos cuantitativamente más documentados que los análisis tradicionales. El análisis léxico de las coocurrencias discursivas aporta datos de interés para interpretar cómo se construyen los discursos. Nuestro interés se sitúa en el empleo de la Lingüística de Corpus como instrumento para el Análisis del Discurso, pues ambas disciplinas presentan en la actualidad metodología adecuada para la interpretación de discursos como auxiliares en el análisis e interpretación de determinados fenómenos significativos. Para ello utilizaremos corpus específicos que nos aportan datos sobre la utilización discursiva de las unidades analizadas. Nos detendremos en determinadas manifestaciones de violencia en textos periodísticos que tienen denominaciones específicas en inglés y en español, no siempre coincidentes.

  1. La movilidad internacional por razones de estudio: Geografía de un fenómeno global

    Directory of Open Access Journals (Sweden)

    Rosa Emilia Bermúdez Rico

    2015-01-01

    Full Text Available El propósito central de este artículo es presentar un análisis de las recientes tendenciasy patrones que caracterizan la movilidad por razones de estudio a nivel terciario comofenómeno mundial, en el contexto general de la movilidad calificada actual. Bajo estemarco se discuten las perspectivas analíticas sobre la movilidad por razones de estudioy se identifican puntos centrales del debate actual en torno al carácter e implicacionesde este tipo de movilidad. El análisis presentado se fundamenta en las estadísticas so-bre movilidad internacional de estudiantes en educación terciaria, suministradas porel Instituto de Estadística de la Organización de Naciones Unidas para la Educacióny la Cultura (UNESCO. El análisis detallado de este flujo, tanto en los países de origencomo de recepción, muestra una geografía de este fenómeno global que se caracte-riza por su concentración hegemónica en los países del norte como receptores y elpredominio de los países asiáticos en la disputa por obtener una mayor cualificaciónprofesional con estándares internacionales en el contexto mundial.

  2. Acciones gubernamentales frente a los desastres provocados por fenómenos hidrometeorológicos en México

    Directory of Open Access Journals (Sweden)

    Gabriel Angelotti Pasteur

    2015-02-01

    Full Text Available Las acciones realizadas tras los desastres constituyen una oportunidad para el cambio social, en específico, para construir sociedades resilientes. Sin embargo, cuando en los procesos de reconstrucción se persiguen intereses exógenos (económicos, sociales o políticos y, preferentemente, ajenos a las necesidades de la sociedad afectada, se incrementan las condiciones de riesgo y la vulnerabilidad ante futuras amenazas. En el presente trabajo se analiza lo ocurrido en Yucatán (México cuando, tras el paso del huracán Isidoro (2002, se implementó un programa de reconstrucción con el fin de suplir aquellas viviendas que habían sido dañadas y destruidas por ese fenómeno hidrometeorológico. Mediante el mismo se esperaba dotar a las familias damnificadas de una vivienda digna, resistente, moderna y, de este modo, contribuir a forjar una sociedad más segura. Sin embargo, los resultados alcanzados ponen en duda esta meta del gobierno.

  3. Acoso sexual: Elementos de discusión para la redefinición del fenómeno

    Directory of Open Access Journals (Sweden)

    Víctor Manuel Aguilar Pereira

    2007-02-01

    Full Text Available LA PROBLEMÁTICA DEL ACOSO SEXUAL SE HA CONFINADO, GENERALMENTE, al ámbito laboral, y se ha considerado como un efecto de relaciones jerárquicas. Esta concepción ha limitado su estudio en cierta medida, y ha permitido que se ignoren otras manifestaciones, mucho más sutiles, pero que, con una mirada más minuciosa y crítica, dejan entrever los cimientos socio-históricos de este fenómeno: la arraigada ideología de género, traducida en violencia de género, que mancilla diariamente los derechos fundamentales de la mujer. Si bien falta un largo camino por recorrer para reformular una definición integral de acoso sexual, los factores aquí presentados se han considerado elementos primordiales para esta reformulación, puesto que permitirán un conocimiento más amplio de las raíces que sustentan al acoso sexual, lo que a su vez encaminará propuestas de acción efectivas para que, tanto hombres como mujeres, puedan hacerle frente.

  4. Estudio exploratorio sobre el fenómeno del “Bullying” en la ciudad de Cali, Colombia

    Directory of Open Access Journals (Sweden)

    María Teresa Paredes

    2008-05-01

    Full Text Available Este es el primer estudio sobre el fenómeno del hostigamiento entre pares o “bullying” que se realiza en la ciudad de Cali, Colombia. Se efectuaron 2.542 encuestas a estudiantes de sexto, séptimo y octavo grados de catorce colegios de la ciudad, con el fin de identificar la presencia del problema y –en caso de existir– de establecer las formas específicas de manifestación, teniendo en cuenta edad, género y estrato socioeconómico.Los resultados demostraron la presencia de “bullying” en el 24.7% de los encuestados y encuestadas, expresado en comportamientos de intimidación o agresión verbal, física y psicológica en estudiantes de ambos géneros de todos los estratos socioeconómicos. Se estableció que la forma de agresión de mayor frecuencia es la verbal y que ésta sucede también en presencia de otros compañeros, compañeras, profesoras y profesores en el aula de clase.

  5. Measurement and modelling of CO2 flux from a drained fen peatland cultivated with reed canary grass and spring barley

    DEFF Research Database (Denmark)

    Kandel, Tanka Prasad; Elsgaard, Lars; Lærke, Poul Erik

    2013-01-01

    -scale ratio vegetation index as an active vegetation proxy. The GP model captures the effect of temperature and vegetation status, and the RE model estimates the proportion of foliar biomass dependent respiration (Rfb) in the total RE. Annual RE was 1887 ± 7 (mean ± standard error, n = 3) and 1288 ± 19 g CO2......Cultivation of bioenergy crops has been suggested as a promising option for reduction of greenhouse gas (GHG) emissions from arable organic soils (Histosols). Here, we report the annual net ecosystem exchange (NEE) fluxes of CO2 as measured with a dynamic closed chamber method at a drained fen...... peatland grown with reed canary grass (RCG) and spring barley (SB) in a plot experiment (n = 3 for each cropping system). The CO2flux was partitioned into gross photosynthesis (GP) and ecosystem respiration (RE). For the data analysis, simple yet useful GP and RE models were developed which introduce plot...

  6. Fen (n=1–6) clusters chemisorbed on vacancy defects in graphene: Stability, spin-dipole moment, and magnetic anisotropy

    KAUST Repository

    Haldar, Soumyajyoti

    2014-05-09

    In this work, we have studied the chemical and magnetic interactions of Fen (n=1–6) clusters with vacancy defects (monovacancy to correlated vacancies with six missing C atoms) in a graphene sheet by ab initio density functional calculations combined with Hubbard U corrections for correlated Fe-d electrons. It is found that the vacancy formation energies are lowered in the presence of Fe, indicating an easier destruction of the graphene sheet. Due to strong chemical interactions between Fe clusters and vacancies, a complex distribution of magnetic moments appear on the distorted Fe clusters which results in reduced averaged magnetic moments compared to the free clusters. In addition to that, we have calculated spin-dipole moments and magnetic anisotropy energies. The calculated spin-dipole moments arising from anisotropic spin density distributions vary between positive and negative values, yielding increased or decreased effective moments. Depending on the cluster geometry, the easy axis of magnetization of the Fe clusters shows in-plane or out-of-plane behavior.

  7. Hacia una caracterización psico-social del fenómeno de callejerización

    Directory of Open Access Journals (Sweden)

    Elvia Taracena Ruiz

    2010-01-01

    Full Text Available En este artículo realizo una reflexión crítica de mis investigaciones durante 20 años de trabajo con jóvenes y niños en situación de calle. Pongo el énfasis en la definición de la problemática en la articulación de tres registros: macro, medio y micro. Describo el marco teórico-metodológico en donde planteo la necesidad de construir un marco multireferencial y transdisciplinario.Cuestiono la relación del sujeto investigador con el problema estudiado y señalo la importancia del análisis de su implicación. Describo las condiciones sociales que propician la salida a la calle de los jóvenes y las jóvenes, y analizo las consecuencias en el sujeto joven en proceso de callejerización del desarrollo del mercado humanitario. Pongo el énfasis en la construcción de un marco teórico- metodológico buscando respetar tanto la singularidad como complejidad del fenómeno a través de una aproximación cualitativa.

  8. Antioxidant activity and phenolic content of agricultural by-products from wine production/ Atividade antioxidante e conteúdo fenólico do resíduo agroindustrial da produção de vinho

    Directory of Open Access Journals (Sweden)

    Eugênia Marta Kuskoski

    2008-08-01

    Full Text Available The present work aimed to investigate the antioxidant properties of byproducts derived from wine production. The varieties of PINOT GRIS and COUDERC 13 grapes, collected in Videira-SC, were analyzed as natural sources of polyphenols and other prophylactic agents (antioxidants for application in food and phytochemical industries. The biomass used for extracts was ground and dried in different temperatures (45oC, 60oC e 80oC, using acetone 80% as solvent. The phenolic compounds were quantitatively evaluated by the Folin-Ciocalteu method and the results expressed in mg/100g of Gallic acid. For the flavonoids analysis, it was applied DMACA (p- Dimethylaminocinnamaldehye method and the results were expressed in equivalent mg of catechin/100g sample. The antioxidant activity was evaluated by spectrophotometric method through the discoloration of ABTS•+ radical (2,2'-azino-bis[3- ethylbenzthiazoline-6-sulfonic acid] with potassium persulphate and by DPPH method, which is based on the reduction of DPPH• radical absorbance by antioxidant substances; the results were expressed in TEAC (antioxidant activity equivalent to Trolox and VCEAC (antioxidant activity equivalent to vitamin C. It was observed a better antioxidant activity on extracts obtained from PINOT GRIS grapes, in which the 45 oC dried extracts presented a higher number of phenolic compounds and flavonoids, as well as a better antioxidant activity in both varieties. These information become useful for phenolic compounds identifying and for a possible using of these extracts as a secure additive in food industry.Este trabalho propõe uma investigação do potencial antioxidante do resíduo no processamento de uvas das variedades COUDERC 13 e PINOT GRIS, ambas coletadas em Videira-SC, como fonte natural de polifenóis e outros agentes profiláticos (antioxidantes para aplicação nas indústrias alimentícia e de fitoterápicos. A biomassa utilizada para obtenção dos extratos foi triturada

  9. Ritmos electrónicos y raves en la mitad del mundo. Etnografía del fenómeno tecno en Ecuador

    Directory of Open Access Journals (Sweden)

    Voirol , Jérémie

    2006-05-01

    Full Text Available El fenómeno tecno ecuatoriano se inicia en Montañita hacia 1992-1993 y se desarrolla principalmente en Quito y Guayaquil. El surgimiento y desarrollo de este fenómeno están marc a d o s por la influencia del movimiento tecno euro p e o - n o rteamericano y es dinamizado por extranjeros que llevan la música al país. Los jóvenes que escuchan tecno y participan en las fiestas provienen de clases altas, y lo utilizan como elemento distintivo y diferenciador con respecto a lo popular, lo cual rechazan. La fiesta tecno es un ritual de fin de semana que marca una ruptura con lo cotidiano (evacuar tensiones, sentimiento de bienestar, etc. y que arraiga a los participantes a lo local, pero a la vez gira en torno a los consumos de cultura europeo-norteamericana.